ECIL ECE EXAM PREVIOUS PAPER

Part 1
1.The current I in the given network.
a) 1A b) 3A c) 5A d) 7A

2.For the Delta- Wye transformation in given figure, the value of the resistance R is.
a) 1/3 ohms b) 2/3 ohms c) 3/2 ohms d) 3 ohms

3.In the given network, the Thevenin’s equivalent as seen by the load resistance Rl is
a) V=10 V, R= 2ohms b) V=10V, R=3 ohms c) V=15V, R= 2ohms d) V=15V, R=3 ohms

4.The current I in a series R-L circuit with R=10 ohms and L=20mH is given by i=2sin500t A. If v is the voltage across the R-L combination then i
a) lags v by 45 degree b) is in-phase with v c) leads v by 45 d) lags v by 90

5.In thr given network, the mesh current I and the input impedance seen by the 50 V source, respectively, are
a) 125/13 A and 11/8 ohms b) 150/13 A and 13/8 ohms c) 150/13 A and 11/8 ohms d) 125/13 A and 13/8 ohms

6.A voltage sourcehaving a source impedance Z = R + jX can deliver maximum Average power to a load impedance Z, when
a) Z = R + jX b) Z = R c) Z = jX d) Z = R –jX

7.In the given circuit, the switch S is closed at t=0. Assuming that there is no initial Charge in the capacitor, the current i(t) for t>0 is
a) V/R e^ (-2t/RC) b) V/R e^ (-t/RC) c) V/2R e^ (-2t/RC) d) V/2R e^ (-t/RC)

8.For the circuit in given figure, if e(t) is a ramp signal, the steady state value of the Output voltage v(t) is
a) 0 b) LC c) R/L d) RC

9.For the series RLC circuit in given figure, if w=1000 rad/sec, then the current I (in Amperes) is
a) 2 ∟-15 b) 2 ∟15 c) √2∟-15 d) √2∟15

10.The Y-parameter matrix (mA/V) of the two-port given network is
a) [2 -1 -1 2] b) [2 1 -1 2] c) [1 -2 -1 2] d) [2 1 1 2]

11.The maximum number of trees of the given graph is
a) 16 b) 25 c) 100 d) 125

12.Given figure shows a graph and one of its trees. Corresponding to the tree, the group of branches that CAN NOT constitute a fundamental cut set is
a) 1,2,3 b) 1,4,6,8,3 c) 5,6,8,3 d) 4,6,7,3

13.The Y-parameter matrix of a network is given by Y=[1 1 -1 1] A/V. The Z11 parameter of the same network is
a) ½ ohms b) 1/√2 ohms c) 1 ohms d) 2 ohms

14.For the given circuit, the switch was kept closed for a long time before opening it at t=0. The voltage v(0+) is
a) -10 V b) -1 V c) 0V d) 10 V

15.The input impedance of a series RLC circuit operating at frequency W=√2w, w being the resonant frequency, is
a) R-j(wL/√2) ohms b) R+j(wL/√2) ohms c) R-j√2wL ohms d) R-j√2wL ohms

16.The threshold voltage V is negative for
a) an n-channel enhancement MOSFET b) an n-channel depletion MOSFET c) an p-channel depletion MOSFET d) an p-channel JFET

17.At a given temperature, a semiconductor with intrinsic carrier concentration ni= 10 ^ 16 / m^3 is doped with a donor dopant of concentration Nd = 10 ^ 26 /m^3. Temperature remaining the same, the hole concentration in the doped semiconductor is
a) 10 ^ 26 /m^3 b) 10 ^ 16 /m^3 c) 10 ^ 14 /m^3 d) 10 ^ 6 /m^3}

18.At room temperature, the diffusion and drift constants for holes in a P-type semiconductor were measured to be Dp = 10 cm^2/s and µp = 1200 cm^2/V-s, respectively. If the diffusion constant of electrons in an N-type semiconductor at the same temperature is Dn = 20 cm^2/s, the drift constant for electrons in it is
a) µn = 2400 cm^2/V-s b) µn = 1200 cm^2/V-s c) µn = 1000 cm^2/V-s d) µn = 600 cm^2/V-s

19.A common LED is made up of
a) intrinsic semiconductor b) direct semiconductor c) degenerate semiconductor d) indirect semiconductor

20.When operating as a voltage regulator, the breakdown in a Zener diode occurs due to the
a) tunneling effect b) avalanche breakdown c) impact ionization d) excess heating of the junction.

21.If the common base DC current gain of a BJT is 0.98, its common emitter DC current gain is
a) 51 b) 49 c) 1 d) 0.02

22.Negative resistance characteristics is exhibited by a
a) Zener diode b) Schottky diode c) photo diode d) Tunnel diode

23.Let En and Ep, respectively, represent the effective Fermi levels for electrons and holes during current conduction in a semiconductor. For lasing to occur in a P-N junction of band-gap energy 1.2 eV, (En - Ep) should be
a) greater than 1.2eV b) less than 1.2eV c) equal to 1.1eV d) equal to 0.7eV

24.In a P-well fabrication process, the substrate is
a) N-type semiconductor and is used to build P-channel MOSFET
b) P-type semiconductor and is used to build P-channel MOSFET
c) N-type semiconductor and is used to build N-channel MOSFET
d) P-type semiconductor and is used to build N-channel MOSFET

25.In a MOS capacitor with n-type silicon substrate, the Fermi potential ¢ = -0.41 V and the flat-band voltage Vfb = 0V. The value of the threshold voltage Vt is
a) -0.82 V b) -0.41 V c) 0.41 V d) 0.82

Refer given figure for question 26 and 27. Assume D1 and D2 to be ideal diodes.
26.Which one of the following statements is true?
a) Both D1 and D2 are ON.
b) Both D1 and D2 are OFF.
c) D1 is ON and D2 is OFF.
d) D2 is ON and D1 is OFF.

27.Values of Vo and I, respectively, are
a) 2V and 1.1 mA b) 0V and 0 mA c) -2V and 0.7 mA d) 4V and 1.3 mA

28.In a BJT CASCODE pair, a
a) common emitter follows a common base
b) common base follows a common collector
c) common collector follows a common base
d) common base follows a common emitter

29.Inside a 741 op-amp, the last functional block is a
a) differential amplifier b) level shifter c) class-A power amplifier d) class-AB power amplifier

30.For the MOSFET in the given circuit, the threshold voltage Vt = 0.5V, the process parameter KP = 150 µA/V^2 and W/L = 10. The values of Vd and Id, respectively, are
a) Vd = 4.5 V and Id = 1 mA
b) Vd = 4.5 V and Id = 0.5 mA
c) Vd = 4.8 V and Id = 0.4 mA
d) Vd = 6 V and Id = 0 mA
31.A negative feedback is applied to an amplifier with the feedback voltage proportional to the output current. This feedback increases the
a) input impedance of the amplifier b) output impedance of the amplifier c) distortion in the amplifier d) gain of the amplifier
32.The early effect in a BJT is modeled by the small signal parameter
a) r0 b) r∏ c) gm d) β
33.For a given filter order, which one of the following type of filters has the least amount of ripple both in pass-band and stop-band?
a) Chebyshev type I b) Bessel c) Chebyshev type II d) Elliptic
34.For a practical feedback circuit to have sustained oscillation, the most appropriate value of the loop gain T is
a) 1 b) -1 c) -1.02 d) 1.02
35.Assume the op-amps in given figure to be ideal. If the input signal vi is a sinusoid of 2V peak-to-peak and with zero DC component, the output signal vo is a
a) sine wave b) square wave c) pulse train d) triangular wave
36.In a common source amplifier, the mid-band voltage gain is 40 dB and the upper cutoff frequency is 150kHz. Assuming single pole approximation for the amplifier the unity gain frequency fT is
a) 6 MHz b) 15 MHz c) 150 MHz d) 1.5 GHz
37.An op-amp is ideal except for finite gain and CMRR. Given the open loop differential gain Ad=2000, CMRR = 1000, the input to the noninverting terminal is 5.002 V and the input to the inverting terminal is 4.999 V, the output voltage of the op-amp is

a) 14 V b) 24 V c) -6 V c) -8 V

38.The op-amp in the circuit in given figure has a non-zero DC offset. The steady state value of the output voltage Vo is
a) –RC dvs(t)/ dt b) – (1/RC)|vs(t)dt c) –V d) +V

39.For the circuit in given figure, if the value of the capacitor C is doubled, the duty-cycle of the output waveform Vo
a) increases by a factor of 2 b) increases by a factor of 1.44 c) remains constant d) decreases by a factor of 1.44

40.Assume the op-amp in the given circuit to be ideal. The value of the output voltage Vo is
a) 3.2 Vi b) 4 Vi c) 9 Vi d) 10 Vi

41.The complement of the Boolean expression F = (X + Y¯ + Z)(X¯ + Z¯)(X + Y) is
a) XYZ+XZ¯+Y¯Z b) X¯YZ¯+XZ+X¯Y¯ c) X¯YZ¯+XZ+YZ d) XYZ+X¯Y¯

42.The Boolean function F(A,B,C,D) = ∑(0,6,8,13,14) with don’t care conditions d(A,B,C,D) = ∑(2,4,10) can be simplified to
a) F = B¯D¯+CD¯+ABC¯ b) F = B¯D¯+CD¯+ABC¯D c) F = AB¯D¯+CD¯+ABC¯ d) F = B¯D¯+CD¯+ABCD

43.The Boolean function F = A¯D¯+B¯D can be realized by one of the following figures

44. For the multiplexer in given figure, the Boolean expression for the output Y is
a) A¯B¯+B¯C¯+AC b) AB¯+B¯C¯+AC¯ c) AB¯+B¯C+AC d) A¯B¯+B¯C+A¯C

45. Which one of the following is TRUE?
a) Both latch and flip-flop are edge triggered.
b) A latch is level triggered and a flip-flop is edge triggered.
c) A latch is edge triggered and a flip-flop is level triggered.
d) Both latch and flip-flop are level triggered.

46. In a schottky TTL gate, the Schottky diode
e) increases the propagation delay
f) increases the power consumption
g) prevents saturation of the output transistor
h) keeps the transistor in cutoff region

47. For which one of the following ultraviolet light is used to erase the stored contents
a) PROM b) EPROM c) EEPROM d) PLA

48. Which one of the following is NOT a synchronous counter
a) Johnson counter b) Ring counter c) Ripple counter d) Up-down counter

49. In 8085 microprocessor, the accumulator is a
a) 4 bit register b) 8 bit register c) 16 bit register d) 32 bit register
50. In the register indirect addressing mode of 8085 microprocessor, data is stored
a) at the address contained in the register pair
b) in the register pair
c) in the accumulator
d) in a fixed location of the memory

51. The output w[n] of the system shown in given figure is
a) x[n] b) x[n-1] c) x[n] – x[n-1] d) 0.5(x[n-1] + x[n])

52. Which one of the following is a periodic signal
a) x(t) = 2 e^j(t+(π/4)) b) x[n] = u[n] + u[-n] c) x[n] = ∑{∂[n-4k]-∂[n-1-4k]} where k = -∞to ∞ d) x(t) = e^ (-1+j)t

53. If the input-output relation of a system is y(t) = ∫x(t) dt where t = -∞ to 2t
a) linear, time-invariant and unstable
b) linear, non-causal and unstable
c) linear, causal and time invariant
d) non-causal, time invariant and unstable

54. Which one of the can be the magnitude of the transfer function | H(jw) | of a causal system

55. Consider the function H(jw) = H1(w) + jH2(w), where H1(w) is an odd function and H2(w) is an even function. The inverse Fourier transform of H(jw) is
a) a real and odd function
b) a complex function
c) a purely imaginary function
d) a purely imaginary and odd function

56. The laplace transform of given signal is
a) –A((1-e^cs)/s) b) A((1-e^cs)/s) c) A((1-e^-cs)/s) d) –A((1-e^-cs)/s)

57. If X(z) is the z-transform of x[n] = (1/2)^ |n|, the ROC of X(z) is
a) |z| > 2 b) |z| <>

58. In a linear phase system, τg the group delay and τp the phase delay are
a) constant and equal to each other b) τg is a constant and τp is proportional to w c) a constant and τg is proportional to w d) τg is proportional to w and τp is proportional to w

59. A signal m(t), band-limited to a maximum frequency of 20 kHz is sampled at a frequency fs kHz to generate s(t). An ideal low pass filter having cut-off frequency 37 kHz is used to reconstruct m(t) from s(t). The maximum value of fs required to reconstruct m(t) without distortion is
a) 20 kHz b) 40kHz c) 57 kHz d) 77 kHz

60. If the signal x(t) shown in given figure is fed to an LTI system having impulse response h(t) as shown in given figure, the value of the DC component present in the output y(t) is
a) 1 b) 2 c) 3 d) 4

61. The characteristic equation of an LTI system is given as s^3 + Ks^2 + 5s + 10. When the system is marginally stable, the value of K and the sustained oscillation frequency w, respectively, are
a) 2 and 5 b) 0.5 and √5 c) 0.5 and 5 d) 2 and √5

62. The time required for the response of a linear time-variant system to reach half the final value for the first time is
a) delay time b) peak time c) rise time d) decay time

63. The signal flow graph of the given network is

64. Let c(t) be the unit step response of a system with transfer function K(s+a)/(s+K). If c(0+)=2 and c(∞)=10, then the values of a and K, respectively, are
a) 2 and 10 b) -2 and 10 c) 10 and 2 d) 2 and -10

65. The loop transfer function of an LTI system is G(s)H(s)= K(s+1)(s+5) / s(s+2)(s+3). For K>0, the point on the real axis that DOES NOT belong to the root locus of the system is
a) -0.5 b) -2.5 c) -3.5 d) -5.5

66. The state space equation of the circuit shown in given figure for x1=v0, x2=I is

67. The open loop gain of a unity feedback system is G(s)=wn^2 / s(s+2wn). The unit step response c(t) of the system is

69. The angles of the asymptotes of the root loci of the equation s^3 + 5s^2 + (K+2)s + K = 0, for 0<=K<∞, are
a) 0 and 270 b) 0 and 180 c) 90 and 270 d) 90 and 180

70. The bode plot corresponding to a proportional derivative controller is the one shown in given figure

71. In frequency modulation, the instantaneous
a) amplitude of the carrier signal is varied with the instantaneous amplitude of the message signal
b) amplitude of the carrier signal is varied with the instantaneous frequency of the message signal
c) frequency of the carrier signal is varied with the instantaneous amplitude of the message signal
d) frequency of the carrier signal is varied with the instantaneous frequency of the message signal

72. If X is a zero mean Gaussian random variable, then P{X<=0} is
a) 0 b) 0.25 c) 0.5 d) 1

73. If a single-tone amplitude modulated signal at a modulation depth of 100% transmits a total power of 15W, the power in the carrier component is
a) 5W b) 10W c) 12W d) 15W

74. In a superheterodyne receiver, rejection of the image signal can be achieved by using a
a) higher local oscillatorn frequency b) crystal oscillator c) narrow band IF filter d) narrow band filter at RF stage

75. The number of bbits per sample of a PCM system depends upon the
a) sampler type b) quantizer type c) number of levels of the quantizer d) sampling rate

76. Which one of the following is used for the detection of AM-DSB-SC signal
a) Ratio detector b) Foster-Seeley discriminator c) Product demodulator d) Balanced-slpoe detector

77. Which one of the following signal pairs can represent a BPSK signal
a) A cos2πfct, A sinπfct
b) A cos2πfct, - A sinπfct
c) - A cos2πfct, A sinπfct
d) A sin2πfct, A cosπfct

78. Which one of the following can be used for the detection of the noncoherent BPSK signal
a) matched filter b) phase-locked loop c) envelope detector
d) product demodulator

79. Bits of duration Tb are to be transmitted using a BPSK modulation with a carrier of frequency Fc Hz. The power spectral density of the transmitted signal has the first null at the normalized frequency
a) |F – Fc|Tb = 0 b) |F – Fc|Tb = 1 c) |F – Fc|Tb = 2 d) |F – Fc|Tb = 4

80. The probability of bit error of a BPSK modulation scheme, with transmitted signal energy per bit Eb, in an additive white Gaussian noise channel having one-sided power spectral density N0, is
a) (1/2) erfc(Eb/2N0) b) (1/2) erfc√(Eb/2N0) c) (1/2) erfc(Eb/N0) d) (1/2) erfc√ (Eb/N0)

81. For a given transmitted pulse p(t), 0<=t<=T, the impulse response of a filter matched to the received signal is
a) –p(t-T), 0<=t<=T b) –p(T-t), 0<=t<=T c) p(t-T), 0<=t<=T d) p(T-t), 0<=t<=T

82. The multiple access communication scheme in which each user is allocated the full available channel spectrum for a specified duration of time is known as
a) CDMA b) FDMA c) TDMA d) MC-CDMA

83. GSM system uses TDMA with
a) 32 users per channel b) 16 users per channel c) 8 users per channel d) 4 users per channel

84. If Rx(τ) is the auto-correlation function of a zero-mean wide-sense stationary random process X, then which one of the following is NOT true?
a) Rx(τ) = Rx(-τ) b) Rx(τ) = -Rx(-τ) c) σx^2 = Rx(0) d) |Rx(τ)| <=Rx(0)

85. If E denotes the expectation operator, then E[X-EX]^3 of a random variable X is
a) EX^3 – E^3X b) EX^3 + 2E^3X – 3EX Ex^2 c) 3EX^3 – E^3X d) 2EX^3 + E^3X – 3EX EX^2

86. A discrete memoryless source produces symbols m1,m2,m3 and m4 with probabilities 1/2, 1/4 , 1/8 and 1/8, respectively. The entropy of the source is
a) ¼ b) 1 c) 7/4 d) 2

87. A channel has a signal-to-noise ratio of 63 and bandwidth of 1200 Hz. The maximum data rate that can be sent through the channel with arbitrary low probability of error is
a) 600 bps b) 1200 bps c) 4800 bps d) 7200 bps

88. For the vectors A = X ax + Y ay and B = Z az, del . (A X B) is
a) 0 b) 1 c) XZ d) YZ

89. Which one of the following relations represents Strokes’ theorem (symbols have their usual meaning)?
a) ∫s del X A.ds = 0 b) ∫L A.dl = ∫s del X A.ds c) ∫s A X dS = -∫v (del X A)dv d) ∫v del.Adv = ∫s A.ds

90. Which one of the following relations is not correct (symbols have their usual meaning)?
a) del X E = - ∂B/∂t b) del X H = J + ∂E/∂t c) del.D = ρv d) del.B = 0

91. The electric field component of a uniform plane wave propagating in a lossless magnetic dielectric medium is given by E(t,z)=ax 5cos(10^9 t – 20/3 z)V/m. If η0 represents the intrinsic impedance of the free space, the corresponding magnetic field component is given by
a) H(t,z)= ay 5/2 η0 cos(10^9t – 20/3 z)A/m
b) H(t,z)= ay 10/ η0 cos(10^9t – 20/3 z)A/m
c) H(t,z)= az 5/2 η0 cos(10^9t – 20/3 z)A/m
d) H(t,z)= az 10/ η0 cos(10^9t – 20/3 z)A/m

92. The skin depth of a non-magnetic conducting material at 100 MHz is 0.15 mm. The distance which a plane wave of frequency 10 GHz travels in this material before its amplitude reduces by a factor of e^-1 is
a) 0.0015 mm b) 0.015 mm c) 0.15 mm d) 1.5 mm

93. A lossless transmission line has a characteristic impedance of 100 ohms and an inductance per unit length of 1 μH/m. If the line is operated at 1 GHz, the propagation constant β is
a) 2π rad/m b) 20π/3 rad/m c) 20π rad/m d) 2π *10^5 rad/m

94. When a load resistance Rl is connected to a lossless transmission line of characteristic impedance 75 ohms, it results in a VSWR of 2. The load resistance is
a) 100 ohms b) 75√2 ohms c) 120 ohms d) 150 ohms

95. A two-port network characterized by the S-parameter matrix, [S] = [0.3 L0 0.9 L90

0.9 L90 0.2 L0]

Is

a) both reciprocal and lossless b) reciprocal, but not lossless c) lossless, but not reciprocal d) neither reciprocal nor lossless

96. A lossless air filled rectangular waveguide has internal dimensions of a cm * b cm. If a=2b and the cutoff frequency of the TE02 mode is 12 GHz, the cutoff frequency of the dominant mode is
a) 1 GHz b) 3 GHz c) 6 GHz d) 9 GHz

97. A Hertzian dipole antenna is placed at the origin of a coordinate system and it is oriented along z-axis. In which one of the following planes the radiation pattern of the antenna has a circular shape?
a) x=0 b) y=0 c) z=0 d) ø=45

98. Which one of the following statements is not true?
a) Antenna losses are taken into account in calculating its power gain
b) For an antenna which does not dissipate any power, the directive gain and the power gain are equal
c) Directivity of an antenna is the maximum value of its directive gain
d) The directive gain of a Hertzian dipole is same in all direction

99. The directivity of a half dipole antenna is
a) 1.0 b) 1.5 c) 1.64 d) 2

100. Which one of the following is not true for a step index optical fibre?
a) It can support multiple modes
b) HE11 mode is its lowest order mode
c) The refractive index of the cladding is higher than that of the core
d) At a given wavelength, single mode operation is possible by proper choice of core diameter, core and cladding refractive indices.

GENERAL ABILITY TEST

101. Sarnath is situated in the state of
a) MP b) Bihar c) Punjab d) UP

102. Green house effect is due to the increase of atmospheric
a) CO2 level b) SO2 level c) CO level d) N2 level

103. In the month of July, it is winter in
a) New York b) Beijing c) Sydney d) London

104. The chairman of the Planning commission of India is
a) The prime minister b) The vice-president c) The union finance minister d) The union commerce minister

105. The satellite launch vehicle that placed a number of satellites ito orbit in May 2008 is
a) PSLV-C7 b) PSLV-C8 c) PSLV-C9 d) PSLV-C10

106.DRDO was formed in
a) 1947 b) 1950 c) 1954 d) 1958

107. SAMYUKTA is developed for the use of
a) Navy b) Army c) Air force d) RAC

108. DARL 202 is a variety of
a) pea b) garlic c) capsicum d) tomato

109. TRISHUL is
a) a surface to surface battlefield missile
b) a quick reaction surface to air missile
c) an intermediate range ballistic missile
d) a supersonic cruise missile

110. HUMSA is a
a) sonar b) tank c) mine d) night vision device

111. The value of 1+2i / 3-4i + 2-I / 5i , where i^2 is -1, is
a) -5/2 b) 5/2 c) 2/5 d) -2/5

112. The particular solution of the differential equation d^2y/dx^2 + 2 dy/dx + 5y = 0 satisfying the conditions y(0)=0 and y’(0)=1 is
a) y=1/2 e^-x cos2x b) y=1/2 e^-x sin4x c) y=1/2 e^-x sin2x d) y=1/2 e^-x cos4x

113. For the vectors A=3i-2j+k and B=2i-k, the value of (A*B).A is
a) 0 b) 1 c) 2 d) 3

114. The orthogonal trajectory of the family of curves x^2-y^2 = a (where a is a constant) and passing through the point (1,1) is
a) y=-1/x b) y=1/x c) y=-x d) y=x
115. The value of the line integral ∫ y^2 dx + 2xydy over the curve x=accost, y=asint is
a) 0 b) 1 c) 2 d) 4

116. The n-th partial sum of the infinite series 1/1*2 + 1/2*3 + 1/3*4+……1/n*(n+1)……..
a) 1/n+1 b) n+2/n+1 c) n/n+1 d) n-1/n+1

117. The complex-valued function f(z)=e^z is analytic for
a) no z b) all z c) real z only d) imaginary z only
118. The inverse of the matrix [ cos A sin A
-sin A cos A] is

a) [ -cos A Sin A b) [cos A sin A} c) [cos A -sin A d) [cos A -sin A
sin A cos A] sin A -cos A] -sin A cos A] sin A cos A]

119. Consider the function f(x) defined as
F(x) = 3x-1, x<0
0, x=0
2x+5, x>0
In the following table, List I shows 4 expressions for limits of f(x) and List II indicates the values of the limits
List I List II
P.Lim x->2 f(x) 1. -1
Q.Lim x->0+ f(x) 2. 9
R.Lim x->0- f(x) 3. -10
S.Lim x->-3 f(x) 4. 5
The correct matches are
a) P-2,Q-4,R-1,S-3 B) P-2,Q-4,R-3,S-1 C) P-4,Q-2,R-1,S-3 D) P-4,Q-2,R-3,S-1

120. Two events A and B with probability 0.5 and 0.7, respectively, have joint probability of 0.4. The probability that neither A nor B happens is
a) 0.2 b) 0.4 c) 0.6 d) 0.8

121. Consider the differential equation
X^2 d^2/dx^2 + x dy/dx + (x^2 - 4)y = 0. The statement which is not true for it is
a) It is a linear second order ordinary differential equation
b) It can not be reduced to a differential equation with constant coefficients
c) X=0 is a regular singular point
d) It is a non-homogeneous second order ordinary differential equation

122. The sum of two numbers is 16 and the sum of their squares is a minimum. The two numbers are
a) 10,6 b) 9,7 c) 8,8 d) 5,11

123. The value of the definite integral 0∫(π/2)^(1/3) x^2 sin(x^3)dx is
a) -1/3 b) 0 c) 1 d) 1/3

124. A circle C2 is concentric with the circle C1 : x^2 + y^2 -4x +6y -12 =0 and has a radius twice that of C1. The equation of the circle C2 is
a) x^2 + y^2 -4x +6y -13 =0 b) x^2 + y^2 -4x +6y -87 =0 c) x^2 + y^2 -4x +6y -100 =0 d) x^2 + y^2 -4x +6y -88 =0

125. Consider the quadratic equation x^2 + px + q =0. If p and q are roots of the equation, the values of p and q are
a) p=0, q=0 only b) p=1, q=-2 only c) p=0, q=0 and p=1, q=-2 d) p=0, q=0 and p=-2, q=1

126. Consider the list of words: etiquette, accommodate, forty, exaggerate, continous, independent, receipt. The number of misspelt words are
a) 1 b) 2 c) 3 d) 4

127. Consider the following sentences
1. A few friends he has are all very rich.
2. Do not insult the weak.
3. The later of the two persons was more interesting.
4. All the informations were correct.
Out of these sentences, the grammatically correct sentence is
a) 1 b) 2 c) 3 d) 4

128. The appropriate auxiliary verb to fill in the blank of the sentence “Gandhi knew that he __ soon be jailed.”is
a) would b) will c) shall d) may

129. The number of missing punctuation marks in the sentence “Rajesh along with Amit went to the market.”is
a) 0 b) 1 c) 2 d) 3

130. The meaning of the word PLAGIARISM is
a) theft of public money b) theft of ideas c) belief in one god d) belief in many gods


132. ACROPHOBIA is the abnormal fear of
a) open spaces b) height c) fire d) water

133. The appropriate pair of prepositions to fill in the blank in the sentence “He was angry __ me, because my remarks were aimed __ him.”is
a) at,to b) with, at c) with, to d) at, for

134. The appropriate word(s) to fill up the blank in the sentence “ I remember __ voices in the middle of the night.”is (are)
a) hear b) to hear c) hearing d) heard

135. The passive voice form of the sentence “I have known him for a long time.”is
a) He is known to me for a long time.
b) He is known by me for a long time.
c) He has been known to me for a long time.
d) He has been known by me for a long time.

136. If kennel is to a dog, then __ is to a hen.
a) nest b) coop c) hole d) stable

137. If NATION is to 5236765, then NOTION is to
a) 573675 b) 563765 c) 576375 d) 557365

138. The next two numbers of the series 3,5,11,21 are
a) 34 and 52 b) 34 and 53 c) 35 and 52 d) 35 and 53

139. A, B and C are three places in India with longitudes 80E, 85 E and 90 E respectively. Which one of the following statements about the local times of the places is true?
a) Local time of C is ahead of that of B.
b) Local time of B is ahead of that of C.
c) Local time of A is ahead of that of C.
d) A, B and C all have the same local time.

140. In this question, notations +, / and * are used as follows
A + B means A is the husband of B.
A / B means A is the sister of B.
A * B means A is the son of B.
With these relations, the relationship
denoted by P / Q * R is
a) P is son of R
b) P is daughter of R
c) P is uncle of R
d) P is father of R

141. If DELHI is written as EDHIL, then PARIS is written as
a) APRIS b) SARIP c) SAPIR d) APISR

142. The number of prime numbers between 10 and 50 is
a) 10 b) 11 c) 12 d) 13

143. The odd one in the list : LAN, TCP/IP, HACKER and KILLER is
a) LAN b) TCP/IP c) KILLER d) HACKER

144. SAW is to carpenter as SCALPEL is to
a) surgeon b) mason c) plumber d) tailor

ANSWERS

1) d)Uttarpradesh
2) a) co2
3) c) sydney
4) a) prime minister
5) c) PSLV C9
6) d) 1958
7) b) army
8) don't know
119) b) quick reaction surface to air missile
110) a) sonar
111 to 25 simple math problem
126) d) 4
127) might be sentence 2
128) b) will
129) c) 2
130) b) theft of ideas
131) c) permanent
132) b) height
133) b) with,at
134)b) to hear
135)d) he has been known by me for a long time
136) b) coop
137)a) 573675
138)d) 35,53
139)a) local time of C is ahead of that of B( not confirmed)
140) b) P is daughter of R
141) d) APISR
142) b) 11
143) c) killr
144) a) surgeon
145)d)
146) c)
147) b)
148) c)
149) b)
150) c)

BEL EXAM GENERAL APTITUDE QUESTIONS

1. In which of the following movements ‘Vande Mataram’ was adotped for the first time as a slogan for agitation?
(A) Revolt of 1857
(B) Partition of Bengal in 1905
(C) Non-cooperation Movement in 1922
(D) Quit India Movement in 1942

2. Who warned Gandhiji not to encourage fanaticism of Muslim religious leaders and their followers?
(A) Agha Khan
(B) AjmaI Khan
(C) Hasan Imam
(D) Mohammad Ali Jinnah

3. Which one of the following is not correct about the Congress Session.of Lucknow, 1916?
(A) Ambika Charan Majumdar was not the president of this session
(B) In this session the reunion between the liberal and the extremist was established
(C) Mahatma was apprised the problems of the peasants Champaran for the first time
(D) None of the above

4. Kanpur conspiracy case was against the leaders of?
(A) Khilafat Movement
(B) Non-cooperation Movement
(C) Communist Movement
(D) Revolutionary Movement

5. In India “Currency Notes issue system” is based on?
(A) Minimum reserve system
(B) Proportional reserve system
(C) Fixed exchange rate system
(D) Full convertibility system

6. ‘Disguised’ unemployment means?
(A) Persons with no jobs
(B) Unemployment among house wives
(C) Unemployment among per sons above 60 years pf age
(D) Employment of more persons in a job which lesser number of persons can perform

7. Which of the following statements are true about the income tax in India?
1. It is a progressive tax,
2. It is a direct tax.
3. It is collected by the Government.

4. It is a proportional tax Select the correct answer from the code given below
Codes:
(A) 1 only
(B) 1 and 2 only
(C) 1,2and3only
(D) 2, 3 and 4 only

8. ‘SIDBI’ has been established to
(A) Finance small scale industries
(B) Finance cottage industries
(C) Finance large scale industries
(D) Finance public sector under takings

9. Gangubai Hangal, who died a few months ago, was a?
(A) Classical singer
(B) Dancer
(C) Painter
(D) Sitar player

10. Deep Joshi has recently been given Raman Magsaysay Award in the category of?
(A) Government service
(B) Public service
(C) Community leadership
(D) Emergent leadership

11. The missing number in the following series:
5,10,13,26,29, 58, 61,…
Is?
(A) 122
(C) 128
(B) 125
(D) 131

12. If 2 jeans and 3 shirts cost Rs. 4,000 and jeans and 2 shirts cost Rs. 3,500, how much does a jeans cost?
(A) Rs. 1,500
(B) Rs 1,000
(C)Rs. 500
(D) Rs. 2,000

13. Which one of the following expresses error in computer data?
(A) chip
(B) byte
(C) bug
(D) bit

14.Assertion (A) Graphite is a good lubricant.
Reason (R) Graphite is good conductor of electricity.
Select the correct answer from the codes given below
Codes:
(A) Both (A) and (R) are true and (A) is the correct explanation of (A)
(B) Both (A) and (A) are true but (H) is not the correct explanation of (A)
(C) (A) is true but (R) is false
(D) (A) is false but (A) is true

15. Acid rain is caused by pollution ot environment by?
(A) Carbon dioxide and Nitrogen
(B) Carbon monoxide and Carbon dioxide
(C) Ozone and Carbon dioxide
(D) Nitrous oxide and Sulphur dioxide

16.Which one of the following is called the ‘metal of future’?
(A)Copper
(B) Iron
(C)Titanium
(D) Aluminum

17. The earliest coins of India were made of ?
(A)Copper
(B) Gold
(C)Lead
(D) Silver

18. The Mongols appeared for the first time on the banks of Indus during the reign of?
(A) Balban
(B) Iltutrnish
(C) Qutubuddin Aibak
(D) Razia

19. The first woman ruler of medieval India was?
(A) Chand Bibi
(B) Durgavati
(C) Noorjahan
(D) Razia

20. The Moplah Rebellion (1921) took place in?
(A) Malabar
(B) Marathawada
(C) Telengana
(D) Vidarbha

21. Which part of the Constitutions of India has been described as the:
Soul of the Constitution ?
(A) Directive principles of State policy
(B) Fundamental rights
(C) Preamble
(D) Right to constitutional remedies

22. The first state to implement the Panchayati Raj System in India was?
(A) Uttar Pradesh
(B) Rajasthan
(C) Gujarat
(D) Karnataka

23. Who has the right to seek advisory opinion of the Supreme Court on any question of law?
(A) Prime Minister
(B) President
(C) Any High Court
(D) All of the above

24. Consider the following statements about the Governor of a State
1. He is appointed by the President.
2. He holds office at the pleasure of the President.
3. The executive power of the: State vests in him.
4. Normally he holds office for five years.
Select the correct answer from the codes given below
(A) l and 2
(B) 1,2 and 3
(C) 1,2 and 4
(D) All the four

25. Which one of the following pairs is not correctly matched ?
(A)Ahmedabad—Sabarmati
(B) Lucknow —Gomti
(C) Bhubaneshwar—Mahanadi
(D) Ujjain-Shipra

26.Dilwara Jain temple is situated at?
(A)Palitana
(B) Mount Abu
(C)Sonagiri
(D) Girinarji

27. Which one of the following is the biggest shipping canal in the world?
(A) Kiel Canal
(B) Panama Canal
(C) Soo Canal
(D) Suez Canal

28. Where was the battle of Plassey fought?
(A)Karnal
(B) Haldighati
(C)Mysore
(D) Bengal

29. Who was the first Vice-President of India?
(A)Dr. S. Radhakrishnan
(B)Dr. Rajendra Prasad
(C)C. V. Raman
(D)Jawahar Lal Nehru

30.. What was the reason behind the mutiny of 1857?
(A) Cartridge containing fat
(B) Frustration in soldiers
(C) Failure of British Government
(D) Administrative research

31.. Which of the following is UHF?
(A) 40MHz
(C) 400 KHz
(B) 400 MHz
(D) 40 KHz

32.. Mass of a particle is m and its momentum is p. Its kinetic energy will be?
(A)mp
(B) ppm
(C) pp/m
(D) pp/2m

33. SI . unit of power is ‘watt. It is equivalent to which of the follow ing?
(A) Kgms^-2
(B)Kgm^-2s^-2
(C) Kgm^-2s^-3
(D) None of these

34. Who among the following cricketers scored the highest runs?
(A) Brien Lara
(B) Sanat Jaysurya
(C) Sachin Tendulkar
(D) Virendra Sehwag

35. Which is the oldest Veda?
(A) Samveda
(B) Rigveda
(C) Yajurveda
(D) Atharvaveda

36. Who was the founder of Pakistan ?
(A) Mohammad Ali Jinna
(B) Liyaquat AIi Khan
(C) Gaffar Khan
(D) Benazir Bhutto

37. Who invented television?
(A)J. L. Baird
(B) Lawrance -
(C) Frederick Trechithic
(D) King Gillette

38. Who invented wireless?
(A)Marconi
(B)Charles Caterin
(C)George Cayley
(D)Zenobe Gramme

39 Which of the following was the battle strategy of Shivaji against Mughals?
(A) Alert army
(B) Large army
(C) Political monopoly
(D) Guerilla warfare

40. Find out the next term of the series?
1,2,4,7,11,………
(A)16
(B) 12
(C) 9
(D) 4

41. Which of the following cities is termed as the Pink city?

(A) Jaipur
(B) Jodhpur
(C) Ajrner
(D) Delhi

42. Who wrote the Meghdoot?
(A)Kalidas
(B) Vatsyayan
(C) Chanakya
(D) Premchand

43. Which of the following is a creation of Maithili-Sharan Gupta?
(A)Saket
(B) Urvashi
(C) Prempachisi
(D) Gatha

44. Which is the longest railway line of the world?
(A) Trans-Siberian
(B) Trans-Canadian
(C) Orient Railway line
(D) Railway line from London to Paris

45. Which of the following states has the highest number of voters?
(A) Uttar Pradesh
(B) Bihar
(C) Rajasthan
(D) Gujarat

ANSWERS:

1	B
2	B
3	A
4	C
5	A
6	D
7	B
8	A
9	A
10	C
11	A
12	C
13	C
14	B
15	D
16	C
17	A
18	B
19	D
20	A
21	D
22	B
23	B
24	D
25	C
26	B
27	D
28	D
29	A
30	B
31	B
32	D
33	C
34	C
35	B
36	A
37	A
38	A
39	D
40	A
41	A
42	A
43	A
44	A
45	A

Model paper For AIR DD Engineering assistants

AIR ENGINEERING ASSISTANTS written test of two hours duration
one paper having 175 objective type questions based on the syllabus of three years Diploma/ B.Sc (Physics) 25 objective type questions on General Knowledge and Current Affairs. Each
question will carry two marks. Negative marking will be resorted for wrong answer. One mark will be deducted for each wrong answer.

Questions on electrostatic ,Wires carrying charge,induced field and potential.Intensity of charged particles ,induced field in circular coil , electromagnet and electromagnetic field ,dipole moment Units like coulomb,unit of force,gauss,potential energy,electrostatics Physics knowledge quizz free

1. A particle is moving uniformly with an angular velocity ω on the circumference of a circle of radius r. The linear velocity will be given by
(a) r ω
(c) r/ ω
(b)2πr ω
(d) ω/r

Ans:a

2. Line spectrum is obtained from the?
(a) Sun
(b) Filament of the bulb
(c) Mercury lamp
(d) Burning coal

Ans:c

3. A moving charge produces:
(a) neither electric field nor magnetic field
(b) electro-static field only
(c) magnetic field only
(d) both magnetic and electro-static fields

Ans:c

4. α, β and γrays emitted from a radioactive source are passed through a 0.5 cm. thick aluminum sheet. The out going radiations will consist of:
(a) α, β and γray
(b) β and γray
(c) γray
(d) αrayrays
Ans:b

5. Light year is a unit of
(a) time
(b) distance
(c) velocity
(d) acceleration

Ans:b
6. It is easier to draw up wooden block along an inclined plane than bang it up vertically principally because:
(a) the friction is reduced
(b) only a part of the weight has to be overcome
(c) the mass becomes smaller
(d) g becomes smaller
Ans:b

7. If a piece of ice floating on the surface of water in a beaker melts completely, the level of water
(a) rises
(b) remains the same
(c) falls
(d) initially rises and then falls
Ans:b

8. A Kelvin thermometer and a Fahrenheit thermometer used to record temperature of melting metal, read the same. What will a celcius thermometer read at that temperature?
(a) 301.25°
(b) 273°
(c) 457°
(d) 760°
Ans:a

9. A hydrogen-filled balloon expands as it rises and may even burst after rising very high in the atmosphere. This happens because:
(a) the temperature increases with height
(b) the temperature decreases with height
(c) the atmospheric pressure increases with height
(d) the atmospheric pressure decreases with height

Ans:d

10. if two substances of equal volumes but of different densities are dropped from the same height simultaneously, then
(a) the body of lower density will reach the earth earlier
(b) both the bodies will reach the earth simultaneously
(c) The body of higher density will reach earlier
(d) It depends upon the place
Ans:b

11. When the bob of a pendulum is at the mean position (minimum displacement) of its motion, its total energy is:
(a) all potential
(b) zero
(c) all kinetic
(d) partly kinetic partly potential
Ans:c

12. A red and a green pencil are taken in a room illuminated with green light. In the room:
(a) both pencils will appear dark
(b) pencils will appear as red and green respectively
(c) red pencil.will appear dark and green pencil as green
(d) red pencil will appear red and green pencil dark

Ans:c

13. The consumption of electrical energy in the household is measured in terms of:
(a) Kilowatt hour
(b) Kilowatts
(c) Joules
(d) Kilo Joules

Ans:a

14. A magnet is placed in earth’s magnetic field with north pole of the magnet pointing north. At the neutral point:
(a) the earth’s magnetic field is zero
(b) the magnet’s magnetic field is zero
(c) the fields of the magnet and the earth are equal and in the same direction
(d) the fields of the magnet and the earth are equal and opposite

Ans:d

15. Sudden fall of a barometer reading indicates:
(a) storm
(b) dry weather
(c) fine weather
(d) cold weather

Ans:a

16. If a ball and a rectangular block of different metal when completely immersed in a liquid, have the same loss of weight, then
(a) ball and rectangular block have same density
(b) ball and rectangular block have Weight in air
(c) ball and rectangular block have same volume
(d) ball and rectangular block have immersed to the same depth

Ans:c

17. If the period of oscillation of a simple pendulum is 4 seconds and we want to convert it into a second pendulum, then we have to:
(a) make the length of the pendulum one fourth of the previous length
(b) double the length of the pendulum
(c) make the length of the pendulum half of the previous length
(d) double the mass of the bob

Ans:a

18. The escape velocity of a body from the earth depends upon:
(a) mass of the body
(b) radius of the earth as well as the value of g
(c) the radius of the earth only
(d) volume of the body

Ans:b

19. A cyclist taking a turn bends inside because:
(a) he feels pleasure in doing so
(b) he increases speed in doing so
(c) he obtains necessary Centripetal force
(d) he avoids accidents
Ans:c

20. If the surface of water in a lake is just going to freeze, then the temperature of water at the bottom is
(a) 0°C
(b) 4°C
(c) 3°C
(d) none of these
Ans:b

21. The tangent law is applicable only when:
(a) there are at least two magnetic fields
(b) there two uniform magnetic fields mutually perpendicular to each other
(c) one strong magnetic field and the other weak magnetic field
(d) in the present magnetic fields one should be horizontal component of the earth’s magnetic field
Ans:b

22. A moving coil galvanometer is converted into an ammeter by putting:
(a) a high resistance in parallel
(b) a low resistance in series
(c) a low resistance in parallel
(d) a high resistance in series
Ans:c

23. Lenz’s law is derived from the law of conservation of:
(a)momentum
(b) energy
(c)charge
(d) magnetism
Ans:b

24. On which one of the factors does the sensivity of a galvanometer depend?
(a) number of the turns of the coil
(b) the temperature of the room
(c) the current flowing in it
(d) the potential difference between the two ends.
Ans:a

25. The wavelength of X-rays is of the order of:
(a) 0.1 cm
(b) 10 ²cm
(c)10 ^-4cm
(d)10 ^-8cm
Ans:d

26. Lamps used for street lighting are connected in
(a) parallel
(b) series and parallel both
(c) series
(d) none of the above
Ans:a

27. A. C. can be measured with the help of:
(a) moving coil galvanometer
(b) hot wire ammeter
(c) tangent galvanometer
(d) galvanometer

Ans:b

28.A p-n junction is said to be forward biased, when
(a) the positive pole of the battery is joined to the p-semiconductor and negative pole to the n-semiconductor
(b) the positive pole of the battery is joined to the n-semiconductor and negative pole of the battery is joined to the p-semiconductor
(c) the positive pole of the battery is connected to n- semiconductor and p- semiconductor
(d) a mechanical force is applied in the forward direction

Ans :a

29. At absolute zero, Si acts as ?

(a) non-metal
(b) metal
(c) insulator
(d) none of these

Ans :a

30. When N-type semiconductor is heated ?
(a) number of electrons increases while that of holes decreases
(b) number of holes increases while that of electrons decreases
(c) number of electrons and holes remain same
(d) number of electron and holes increases equally.
Ans :d

31. Radiowaves of constant amplitude can be generated with
(a) FET
(b) filter
(c) rectifier
(d) oscillator

Ans :d

32. In a common base amplifier the phase difference between the input signal voltage and the output
voltage is ?
(a) 0
(b) pi/4
(c)pi/2
(d) p
Ans :d
33. When a triode is used as an amplifier the phase difference between the input signal voltage and
the output is ?
(a) 0
(b)pi
(c) pi/2
(d)pi/4

Ans :b

34. The depletion layer in the P-N junction region is
caused by?
(a) drift of holes
(b) diffusion of charge carriers
(c) migration of impurity ions
(d) drift of electrons

Ans: b
35. The following truth table corresponds to which Logic gate

A	B	Output
0	0	0
0	1	1
1	0	1
1	1	1

(a)NAND
(b) OR
(c)AND
(d) XOR

Ans :b

36. To use a transistor as an amplifier
(a) The emitter base junction is forward biased and the base collector junction is reversed biased
(b) no bias voltage is required
(c) both junction are forward biased
(d) both junctions are reversed biased.

Ans :a

37. Which one of the following is the weakest kind of the bonding in solids
(a) ionic
(b) metallic
(c) Vander Walls
(d) covalent
Ans :c

38.For amplification by a triode, the signal to be amplified is given to
(a) the cathode
(b) the grid
(c) the glass-envelope
(d) the anode
Ans :b

39. A piece of copper and other of germanium are cooled from the room temperature to 80K, then

(a) resistance of each will increase
(b) resistance of copper will decrease
(c) the resistance of copper will increase while that of germanium will decrease
(d) the resistance of copper will decrease while that of germanium will increase
Ans:d

40. Diamond is very hard because ?
(a) it is covalent solid
(b) it has large cohesive energy
(c) high melting point
(d) insoluble in all solvents
Ans:b

41. The part of the transistor which is heavily doped to produce large number of majority carriers is

(a) emitter
(b) base
(c) collector
(d) any of the above depending upon the nature of transistor

Ans:a
42. An Oscillator is nothing but an amplifier with

(a) positive, feedback
(b) negative feedback
(c)large gain
(d) no feedback
Ans:a

43. When a P-N junction diode is reverse biased the flow of current across the junction is mainly due
to
(a) diffusion of charge
(b) drift charges
(c) depends on the nature o material
(d) both drift and diffusion of charges

Ans:b

44. Which of the following gates corresponds to the truth table given below?

A	B	Output
1	1	0
0	1	1
1	0	1
0	0	1

(a) NAND
(b) OR
(c) AND
(d) XOR

Ans:a

45. Which of the following, when added as an impurity, into the silicon, produces n-type semi conductor
(a)Phosphorous
(b) Aluminium
(c)Magnesium
(d) both ‘b’ and ‘c’

Ans:a

46. The current gain for a transistor working as common-base amplifier is 0.96. If the emitter current is 7.2 mA, then the base current is
(a)0.29mA
(b)0.35mA
(c)0.39 mA
(d) 0.43 mA

Ans:a
47. When a n-p-n transistor is used as an amplifier then ?
(a) the electrons flow from emitter to collector
(b) the holes flow from emitter to collector
(c) the electrons flow from collector to emitter
(d) the electrons flow from battery to emitter
Ans:a

48. When arsenic is added as an impurity to silicon, the resulting material is?
(a) n-type semiconductor
(b) p-type semiconductor
(c) n-type conductor
(d) Insulator

Ans:a

49. To obtain a p-type germanium semiconductor,it must be doped with ?
(a)arsenic
(b)antimony
(c)indium
(d)phosphorus
Ans:a

50. A semi-conducting device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. The device may be
(a) A p-n junction
(b) An intrinsic semi-conductor
(c) A p-type semi-conductor
(d) An n-type semi-conductor

Ans:a

51. The transfer ratio beta of a transistor is 50. The input resistance of the transistor when used in the common emitter configuration is 1 kOhm. The peak value of the co current for an A.C. input voltage of 0.01 V peak is ?
(a)100 microA
(b) 0.01 mA
(c)0.25 mA
(d) 500 microA
Ans:d

52. The cause of the potential barrier in a p-n diode is ?
(a) Depletion of positive charges near the junction
(b) Concentration of positive charges near the junction
(c) Depletion of negative charges near the junction
(d) Concentration of positive and negative charges near the junction
Ans:d

53. In forward bias, the width of potential barrier in a p-n junction diode?
(a)increases
(b) decreases
(c) remains constant
(d) first increases then decreases

Ans:b

54. A depletion lay consists of?
(a)electrons
(b) protons
(c)mobile ions
(d) immobile ions

Ans:d
55. Which of the following when added acts as an impurity into silicon produced n-type semi
conductor?
(a)P
(b) Al
(c)B
(d) Mg

Ans:a

56. In a junction diode, the holes are due to
(a) protons
(b) extra electrons
(c) neutrons
(d) missing electrons

Ans:d

57. The intrinsic semiconductor becomes an insulator at
(a)0°C
(b)0K
(c) 300K
(d) —100°C

Ans:b

58. For a common emitter circuit if I_C/I_E = 0.98 then current gain for common emitter circuit will be
(a)49
(b)98
(e)4.9
(d) 25.5
Ans:a

59. In a p-n junction
(a) The potential of the p and n sides becomes higher alternately
(b) The p side is at higher electrical potential than the n side
(c) The n side is at higher electrical potential than the p side
(d) Both the p and n sides are at the same potential

Ans:b

60. In the case of a common emitter transistor amplifier the ratio of the collector current to the emitter current I_c/I_e is 0.96. The current gain of the amplifier is ?
(a)6
(b)48
(c) 24
(d) 12

Ans:c

61. if a full wave rectifier circuit is operating from 5oHz mains, the fundamental frequency in the
tipple will be
(a)100Hz
(b) 25Hz
(c)50Hz
(d) 70.7 Hz

Ans:a
62. A n-p-n transistor conducts when ?
(a) both collector and emitter are negative with respect to, the base
(b) both collector and emitter are positive with respect to the base
(c) collector is positive and emitter is negative with to the base
(d) collector is positive and emitter is at same potential as the base

Ans:c

63. Barrier potential of a p-n junction diode does not depend on?
(a)doping density
(b) diode design
(c)temperature
(d) forward bias

Ans:b

64. Reverse bias applied to a junction diode
(a) increases the minority carrier current
(b) lowers the potential barrier
(c) raises the potential barrier
(d) increases the majority carrier current

Ans:c

65. In semiconductors at a room temperature

(a) the conduction band is completely empty
(b) the valence band is partially empty and the conduction band is partially filled
(c) the valence band is completely filled and the conduction band is partially filled
(d) the valence band is completely filled

Ans:c

66. The output of OR gate is 1 when?
(a) if either input is zero
(b) if both inputs are zero
(c) if either or both inputs are 1
(d) only if both inputs are I
Ans:c

67. In a p-n junction photo cell, the value of the photo-electromotive force produced by monochromatic light is proportional to ?
(a) the voltage applied at the p-n junction
(b) the barrier voltage at the p-n junction
(c) the intensity of the light falling on the cell
(d) the frequency of the light falling on the cell
Ans:c

68. Choose the only false statement from the following.
(a) in conductors the valence and conduction bands may overlap.
(b) Substances with energy gap of the order of 10 eV are insulators.
(c) The resistivity of a semiconductor increases with increase in temperature.
(d) The conductivity of a semiconductor increases with increase in temperature.

Ans:c

69. Carbon, Silicon and Germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by (E_g)_C, (E_g)_Si and (E_g)_Ge respectively. Which one of the following relationship is true in their case?
(a) (E_g)_C> (E_g)_Si
(b) (E_g)_C< (E_g)_Si
(c) (E_g)_C=(E_g)_Si
(d) (E_g)_C< (E_g)_Ge
Ans:a
70. Application of a forward bias to a p—n junction
(a) widens the depletion zone.
(b) increases the potential difference across the depletion zone.
(c) increases the number of donors on the n side.
(d) increases the electric field in the depletion zone.

Ans:c

71. Zener diode is used for?
(a) Amplification
(b) Rectification
(c) Stabilisation
(d) Producing oscillations in an oscillator

Ans:c

72. A current carrying coil is subjected to a uniform magnetic field. The coil will orient so that its
plane becomes ?
(a) inclined at 45° to the magnetic field
(b) inclined at any arbitrary angle to the
magnetic field
(c) parallel to the magnetic field
(d) perpendicular to magnetic field

Ans:c

73. Tesla is the unit of
(a) magnetic flux
(b) magnetic field
(c) magnetic induction
(d) magnetic moment
Ans:b

74. Energy in a current carrying coil is stored in the
form of ?
(a) electric field
(b) magnetic field
(c) dielectric strength
(d) heat

Ans:b

75. The total charge induced in a conducting loop when it is moved in magnetic field depends on?
(a) the rate of change of magnetic flux
(b) initial magnetic flux only
(c) the total change in magnetic flux
(d) final magnetic flux only.
Ans:c

76. The magnetic induction at a point P which is at the distance of 4 cm from a long current carrying wire is 10^-3 T. The field of induction at a distance 12 cm from the current will be ?
(a) 3.33 x 10^-4 T
(b) 1.11x 10^-4 T
(c) 3×10^-3 T
(d) 9×10^-3 T

Ans:a

77. A charge moving with velocity v in X-direction is subjected to a field of magnetic induction in negative X-direction. As a result, the charge will

(a) remain unaffected
(b) start moving in a circular path in Y—Z plane
(c) retard along X-axis
(d) moving along a helical path around X-axis
Ans:a

78. A uniform magnetic field acts right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of radius 2cm. If the speed of electrons is doubled, then the radius of the circular path will be ?
(a)2.0 cm
(b) 0.5 cm
(c)4.0cm
(d) 1.0cm

Ans:c

79. A deuteron of kinetic energy 50 keV is describing a circular orbit of radius 0.5 metre in a plane perpendicular to magnetic field B. The kinetic energy of the proton that describes a circular orbit of radius 0.5 metre in the same plane with
the same B is
(a)25 keV
(b) 50 keV
(c)200 keV
(d) 100 keV

Ans:d

80. A straight wire of length 0.5 metre and carrying a current of 1.2 ampere is placed in uniform magnetic field of induction 2 Tesla. The magnetic field is perpendicular to the length of the wire. The force on the wire is ?
(a) 2.4N
(b) 1.2N
(c) 3.0 N
(d) 2.0 N
Ans:b

81. To convert a galvanometer into an ammeter, one needs to connect a ?
(a) low resistance in parallel
(b) high resistance in parallel
(c) low resistance in series
(d) high resistance in series.
Ans:a

82. A coil carrying electric current is placed in uniform magnetic field
(a) torque is formed
(B) e.m.f is induced
(c) both (a) and (b) are correct
(d) none of the above
Ans:a

83. The magnetic field at a distance ‘r’ from a long wire carrying current ‘i’ is 0.4 Tesla. The magnetic field at a distance ‘2r’ is ?
(a)0.2Tesla
(b) 0.8 Tesla
(c)0.1 Tesla
(d) 1.6 Tesla
Ans:a

84. A electron enters a region where magnetic (B) and electric (E) fields are mutually
perpendicular, then ?
(a) it will always move in the direction of B
(b) it will always move in the direction of E
(c) it always possesses circular motion
(d) it can go un deflected also.
Ans:d

85. A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by another wire of I mm diameter carrying same current. The strength of magnetic field far away is?
(a) twice the earlier value
(b) same as the earlier value
(c) one-half of the earlier value
(d) one-quarter of the earlier value

Ans:b

86. At what distance from a long straight wire carrying a current of 12 A will the magnetic field
be equal to 3×10^-6 Wb/metre Square
(a) 8×10^-2 m
(b) 12×10^-2 m
(c)18x 10^-2 m
(d) 24×10^-2 m

Ans:a

87. An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to ?
(a) ?(B/v)
(b) B/v
(c) ?(v/B)
(d)v/B

Ans:d

88. A 10 eV electron is circulating in a plane at right angles to a uniform field at magnetic induction 10^-4 Wb/m² (= 1.0 gauss). The orbital radius of the electron is ?
(a) 12cm
(b) 16cm
(c) 11cm
(d) 18cm
Ans:c

89. A galvanometer acting as a voltmeter will have?

(a) a low resistance in series with its coil.
(b) a high resistance in parallel with its coil
(c) a high resistance in series with its coil
(d) a low resistance in parallel with its coil
Ans:c

90. A beam of electrons is moving with constant velocity in a region having simultaneous perpendicular electric and magnetic fields of strength 20 Vm^-1 and 0.5 T respectively at right angles to the direction of motion of the electrons. Then the velocity of electrons must be?
(a) 8m/s
(b) 20 m/s
(c) 40m/s
(d) 1/40 m/s

Ans:c

91. A galvanometer of resistance 20 Ohms gives full scale deflection with a current of 0.004 A. To convert it into an ammeter of range 1 A, the required shunt resistance should be?

(a) 0.38 Ohms
(b) 0.21 Ohms
(c) 0.08 Ohms
(d) 0.05 Ohms
Ans:c

92. A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is ?
(a) 4B
(b) B/2
(c) B
(d) 2B
Ans:c

93. A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
(a) continue to move due east
(b) move in a circular orbit with its speed unchanged
(c) move in a circular orbit with its speed increased
(d) gets deflected vertically upwards.

Ans:b
94. Two long parallel wires are at a distance of 1 metre. Both of them carry one ampere of current The force of attraction per unit length between the two wires is?
(a)2 x10^-7 N/m
(b) 2 x10^-8 N/m
(c) 5×10^-8 N/m
(d)10^-7 N/m

Ans:a

95. A galvanometer having a resistance of 8 ohms is shunted by a wire of resistance 2 ohms. If the total current is 1 amp, the part of it passing through the shunt will be?
(a)0.25 amp
(b) 0.8 amp
(c)0.2 amp
(d) 0.5 amp

Ans:b

96. A coil of one turn is made of a wire of certain length and then from the same length a coil of two turns is made. If the same current is passed in both the cases, then the ratio of the magnetic inductions at their centres will be?
(a)2:1
(b)1:4
(c)4:1
(d)1:2
Ans:b

97. Magnetic field intensity in the centre of coil of 50 turns, radius 0.5 m and carrying a current of
2A is ?
(a) 0.5 x 10^-5 T
(b) 1.25x 10^-4 T
(c) 3x 10^-5 T
(c) 4 x 10^-5 T

Ans:b

98. When a proton is accelerated through I V, then its kinetic energy will be?
(a)1840 eV
(b) 13.6eV
(c)1 eV
(d) 0.54eV

Ans:c

99. If a long hollow copper pipe carries a current,thin magnetic field is produced
(a)inside the pipe only
(b)outside the pipe only
(c)both inside and outside the pipe
(d) no where

Ans:b

100. A charged particle moves through a magnetic field in a direction perpendicular to it. Then the

(a) velocity remains unchanged
(b) speed of the particle remains unchanged
(c) direction of the particle remains unchanged
(d) acceleration remains unchanged
Ans:b

101. Which one of the following physical quantities, is not defined in the terms of force per unit area:
(a) pressure
(b) strain
(c) stress
(d) Young’s modulus

Ans:b

102. The distance moved by a moving body is equal to:
(a) area between the distance-time graph and distance axis
(b) area between the speed-time graph and time axis
(c) area between the distance-time graph and time axis
(d) area between the speed-time graph and distance axis.
Ans:b

103. A beaker containing water weighs 100 gm. It is placed on the pan of a balance and a piece of metal weighing 70 gm. and having a volume of 10cc. is placed inside the water in the beaker. The weight of the beaker and the metal would be :
(a) 170gm.
(c) 100gm.
(b)160gm.
(d)30gm.
Ans:a

104. For the same kinetic energy, the momentum shall be maximum for:
(a) electron
(b) proton
(c) deuteron
(d) alpha particle
Ans:d

105. The common balance works on the principle of equality of:
(a) forces
(b) moments of forces
(c) masses
(d) masses of pans
Ans:b

106. A particle moves in a circle of radius R with a constant speed under a centripetal force F. The work done in completing a full circle is:

(a) 2RF
(b) ?R²F
(c) 2?RF
(d)Zero

Ans:d
107. When two quantities are plotted on the graph paper against each other and the result so obtained is a st. line, then
(a) Both the quantities are equal
(b) The quantities are inversely proportional to each other
(c) Sum of both is zero
(d) The quantities are proportional to each other
Ans:d

108. What is the order of magnitude of 260°?
(a)10³
(b) 10⁴
(c)10²
(d) 10
Ans:c

109. The maximum value of g is:
(a) At the poles
(b) At the top of the Mount Everest
(c) At the equator
(d) Below the sea level
Ans:a

110. A fixed volume of gas at 27°C exerts a pressure of 750 mm. If the gas is heated to a pressure of 1500mm., temperature must be:
(a) 600°C
(b) 327°C
(c) 54°C
(d) 13.5°C
Ans:b

111. A body of mass 2 kg acted upon by a constant force, travels a distance of 3 metres in the first second and a further distance of meter in the next second. The force acting on the body is?
(a) 12 Newtons
(b) 8 Newtons
(c) 4 Newtons
(d) 1 Newton

Ans:c

112. Two forces each equal to P acting at a point have no resultant. The angle between the two forces must be equal to:
(a)180°
(b) 90°
(c)0°
(d) 120°

Ans:a

113. A jet engine works on the principle of:
(a) conservation of energy
(b) conservation of momentum
(c) conservation of mass
(d) conservation of temperature

Ans:b

114. A sharp knife cuts much better than a blunt one because?
(a) Area of sharp knife is much less than the area of the blunt one
(b) sharp knife is brighter
(c) sharp knife is colder
(d) sharp knife is costly
Ans:a

115. A man carries a heavy box on his head on a horizontal plane from one place to another.
In this he does?
(a) maximum work
(b) no work
(c) negative work
(d) minimum work
Ans:b

116. The bob of a second’s pendulum is replaced by another bob of double mass. The new time period will be:
(a) 4 sec.
(c) 2 sec.
(b) 1 sec
(d) 3 sec.

Ans:c

117.A device for measuring temperatures at a distance is
(a) gas thermometer
(b) mercury thermometer
(c) radiation
(d) maximum-minimum thermometer

Ans:c

118. A piece of ice is floating in a concentrated solution of common salt (in water) in a pot. When ice melts completely, the level of solution will:
(a) go up
(b) remain the same
(c) go down
(d) first go up then go down

Ans:a

119. A radioactive source has a half-life of 30 days. During a period of 90 days the fraction of atoms that have decayed would be
(a)100%
(b) 87.5%
(c)64%
(d) 50%

Ans:b

120. A black body emits:
(a) radiations of all wavelengths
(b) no radiations
(c) radiations of only one wavelength
(d) radiations of selected wavelengths

Ans:a

121. A near sighted person cannot see distinctly beyond 50 cm. from his eye. The power in diopter of spectacle lenses which will enable him to see distant objects clearly is
(a) +50
(b) —50
(c) +2
(d) —2
Ans:c

122. Size of a nucleus is of the order of?
(a)10^-18m
(b) 10^-14m
(c)10^-10m
(d) 10^-6m
Ans:b

123. The freezing point on a thermometer is marked as 20° and the boiling point as 150°C. A temperature of 60°C on this thermometer will be read as:
(a)40°
(b) 65°
(c)98°
(d) 110°
Ans:c

124. In isothermal expansion of an ideal gas:
(a) heat content remains constant
(b) temperature remains constant
(c) both heat content and temperature remain constant
(d) pressure and temperature of the gas remain constant
Ans:b

125. A man standing between two cliffs hears the first echo of a sound after 2 sec. and the second echo 3 sec. after the initial sound. If the speed of sound be 330 m/sec. the distance between the two cliffs should be
(a)1650 m.
(b)990 m.
(c)825 m
(d) 660 m.
Ans:c

126. In a resonance tube experiment the first resonance is obtained for 10 cm. of air column and the second for 32 cm. The end correction for this apparatus is equal to?
(a)0.5 cm
(b)1.0 cm
(c)1.5 cm
(d) 2 cm
Ans:b

127. The ratio of the specific heat of air at constant pressure to its specific heat at constant volume is?
(a) zero
(b) greater than one
(c) less than one
(d) equal to one

Ans:b

128. A convex lens has a focal length of 10 cm. When it is immersed in water it will behave
as?
(a) a convex tens of 10 cm. focal length
(b) a concave lens of 10 cm. focal length
(c) a convex lens of focal length greater than 10cm.
(d) a convex lens of focal length less than 10 cm.
Ans:c
129. Two particles having charges q1 and q2 when kept at a certain distance exert a force F on each other. If the distance between the two particles is reduced to half and the charge on each particle is doubled the force between the particles would be ?
(a)2F
(b)4F
(c)8F
(d)16F
Ans:d

130. A small magnet is placed perpendicular to a constant magnetic field. The forces acting on the magnet will result in?
(a) rotation
(b) translation
(c) no motion at all
(d) rotation as well as translation
Ans:a

131. A hollow metallic sphere is charged. Inside the sphere?
(a) the potential is zero but the electric field is finite
(b) the electric field is zero but the potential is finite
(c) both the electric field and the potential are finite
(d) both the electric field and the potential are zero
Ans:b

132. Two electric lamps each of 100 watts 220 V are connected in series to a supply of 220 volts. The power consumed would be:
(a)100 Watts
(b) 200 Watts
(c)25 Watts
(d) 50 Watts
Ans:d

133. A transformer is:
(a) a device for stepping up D.C.
(b) a generator of current
(c) device for converting direct current into alternating current
(d) a device for stepping up or down the voltage of A.C. supply
Ans:d

134. Transistor act as a?
(a) conductor
(b) semi-conductor
(c) insulator
(d) thermionic valve

Ans:d

135. The sky is blue because:
(a) there is more blue light in the sunlight
(b) of scattering of sunlight by air molecules in the atmosphere
(c) of scattering of sunlight by dust particles in the atmosphere
(d) other colours are absorbed by heavenly bodies
Ans:b

136. A cyclonic storm is indicated by a change in the atmospheric pressure. In atmospheric
pressure there is a:
(a)sudden rise
(b) gradual rise
(c)sudden fall
(d) gradual fall
Ans:c

137. The electric field inside a hollow conducting sphere will ?
(a) increases towards the centre
(b) decreases towards the centre
(c) is finite and constant throughout
(d) is zero
Ans:d

138. Imperfect gases are those:
(a) which contain impurities
(b) which do not obey Charle’s and Boyle’s laws
(c) whose molecules are not spherical
(d) whose molecules cannot be regarded as point masses
Ans:b

139. Sonar is a device for:
(a) location and ranging of aircraft’s
(b) location and ranging submarines
(c) producing a musical note of high quality
(d) measuring frequency of musical notes
Ans:b

140. Cyclotron is a device to produce:
(a) atomic energy
(b) high energy electrons
(c) high energy photons
(d) high energy protons
Ans:d

141. Which one of the following is not a vector?
(a) Velocity
(b) Acceleration
(c) Force
(d) Energy
Ans:d

142. Two steel balls of mass 1 kg. and 2kg. and a lead ball of 10kg. are released together from the top of tower 30 metres high. Assuming the path to be in vacuum
(a) the lead ball reaches the ground earlier
(b) the 1 kg. steel bail reaches the ground earlier
(c) all the balls reach the ground simultaneously
(d) the 2 kg. steel ball reaches the ground earlier
Ans:c

143. After a watch has been wound, it?
(a) has great energy stored in it
(b) possesses mechanical potential energy stored in it
(c) has eletrical energy stored in it
(d) has no energy in it
Ans:b

144. Two plane mirrors are set at right angles and a flower is placed in any position in between the mirrors. The number of images of the flower which will be seen is?
(b) two
(d) four
(a) one
(c) three
Ans:c

145. In which of the following cases total internal reflection cannot be obtained?
(a) ray going from water to glass
(b) a ray going from glass to water
(c) a ray going from glass to air
(d) a ray going from water to air.
Ans:a

146. When white light passes through a glass prism, we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is
(a) the violet ray
(b) the red ray
(c) the green ray
(d) the yellow ray
Ans:b

147. Magnetic storms are due to
(a) the rotation of the earth
(b) the revolution of the earth
(c) the rainy season
(d) the appearance off Sun spots
Ans:d

148. For dynamo which one of the following statements is correct ?
(a) It converts the electrical energy into light energy
(b) It converts the kinetic energy into heat energy
(c) It converts the mechanical energy into electrical energy
(d) Jt converts the electrical energy into mechanical energy.
Ans:c

149. In a transformer the immediate cause of the induced A. C. in the secondary coil is?
(a) a varying electric field
(b) a varying magnetic field
(e) a motion of the secondary coil
(d) efficiency of the operator
Ans:b

150.A dynamo actually acts as a?
(a) converter of energy
(b) source of electric charge
(c) source of magnetic charge
(d) source of energy
Ans:a

151. Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance of 5 m between them. If P and Q carry current of 2.5 amp and 5 amp respectively in the same direction, then the magnetic field at a point half-way between the wires is ?

(a)3µ/2?
(b)µ/?
(c)?3µ/2?
(d)µ/2?
Ans:a

152. A proton moving with a velocity 3 x 10⁵ m/s enters a magnetic field of 0.3 Tesla at an angle of 30° with the field. The radius of curvature of its path will be (e/m for proton – 10⁸ C/kg)
(a)2cm
(b) 0.5 cm
(c)0.02 cm
(d) 1.25 cm

Ans:b

153. A charged particle of charge q and mass m enters perpendicularly in a magnetic field B. Kinetic energy of the particle is E; then frequency of rotation is?
(a)qB/m∏
(b) qB/2m∏
(c)qBE/2m∏
(d) qB/2E∏

Ans:b

154. A galvanometer can be converted into a voltmeter by connecting?
(a) A high resistance in parallel
(b) A low resistance in series
(c) A high resistance in series
(d) A low resistance in parallel
Ans:c

155. A wire carries a current. Maintaining the same current it is bent first to form a circular plane coil of one turn which produces a magnetic field B at the centre of the coil. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre of the double loop, caused by the same current is ?
(a)4B
(b) B /4
(c) B/2
(d) 2B
Ans:a

156.A bar magnet is oscillating in earth’s magnetic field with a period T. What happens to its period of motion, if its mass is quadruped ?
(a) Motion remains simple harmonic with new period =T/2
(b) Motion remains simple harmonic with new period = 2 T
(c) Motion remains simple harmonic with new period =4T
(d) Motion remains simple harmonic and the period stays nearly constant
Ans:b

157. The work done in turning a magnet of magnetic moment M by an angle of 90° from the meridian, is n times the corresponding work done to turn it through an angle of 60°.
The value of n is given by
(a)2
(b) 1
(c) 0.5
(d) 0.25
Ans:a

158 . For protecting a sensitive equipment from the external electric arc, it should be ?
(a) Wrapped with insulation around it when passing current through it
(b) Placed inside an iron can
(c) Surrounded with fine copper sheet
(d) Placed inside an aluminium can
Ans:b

159. If a diamagnetic substance is brought near north or south pole of a bar magnet, it is?
(a) attracted by the poles
(b) repelled by the poles
(c) repelled by north pole and attracted by the south pole
(d) attracted by the north pole and repelled by the south pole

Ans:b

160. Current i is flowing in a coil of area A and number of turns N, then magnetic moment of
the coil is M= ?

(a) NiA
(b) Ni/A
(c)Ni/?A
(d) N²Ai

Ans:a

161. Two magnets of magnetic moments M and 2M are placed in a vibration magnetometer, with the identical poles in the same direction. The time period of vibration is T₁. If the magnets are placed with opposite poles together and vibrate with time period T₂ then ?
(a) T₂ is infinite
(b) T₂=T₁
(c)T₂>T₁
(d) T₂ is less than T₁

Ans:c
162. A diamagnetic material in a magnetic field moves
(a) perpendicular to the field
(b) from stronger to the weaker pans of the field
(c) from weaker to the stronger parts of the field
(d) in none of the above directions
Ans:b
163. According to Curie’s law, the magnetic susceptibility of a substance at an absolute
temperature T is proportional to?
(a) T²
(b) 1/T
(c) T
(d) 1/T²

Ans:b