Sunday, July 10, 2011

ELECTRICAL ENGINEERING MCQs

1.         Ohm’s law applicable for
(a)        linear circuits only
(b)        non linear circuits only
(c)        both linear  and non linear circuits                                    
(d)       none of these
Ans: a
2.         Unit of current is
(a)        Ampere
(b)        Volt
(c)        Watt                                                                              
(d)       Volt-ampere
Ans: a
3.         What is the equivalent resistance when 10 Ohms and 20 Ohms resistors are connected
in series
(a)        35 Ohms
(b)        25 Ohms
(c)        30Ohms                                                                                
(d)       none of these
Ans: c
4.         Form factor is defined as the ratio of
(a)        Average value to Maximum value
(b)        Maximum value to Average value
(c)        Peak value to R.M.S Value
(d)       R.M.S Value to Average value                                          
Ans: d
5.         R.M.S Value of full wave rectified    sinusoidal voltage is
(a)        VM/3
(b)        VM/2
(c)        VM/Ö2                                                                                 
(d)       none of these
Ans: c
6.         Power factor for resistive load is
(a)        Zero
(b)        Unity
(c)        Infinity                                                                                   
(d)       0.2
Ans: b
7.         voltage is a ——quantity
(a)        Scalar
(b)        Vector
(c)        Scalar and Vector                                                                
(d)       none of these
Ans: b
8.         In D.C , Capacitor acts  as
(a)        Short circuit
(b)        Open circuit
(c)        either (a)or (b)
(d)       none of these         
Ans: b
9         In 3 phase star circuit, phase voltage is
(a)        VPh =Ö3 VL
(b)        VPh = VL /Ö3
(c)        VPh = VL
(d)       VPh =3 VL
Ans: b
10.       In 3 phase delta circuit, line current is
(a)        IL =I Ph
(b)        IL =2 I Ph
(c)        IL =3 I Ph
(d)       IL =Ö3 I Ph
Ans:d
11.       What is the equivalent resistance when 20Ohms and 20Ohms resistors are
connected  in parallel
(a)        45 Ohms
(b)        10Ohms
(c)        54     Ohms                                                                                   
(d)       30Ohms
Ans: b
12.       Voltage-Current relationship in resistor element is
(a)        In phase
(b)        Out of phase
(c)        No Relation
(d)       constant                                                                                
Ans:a
13.       For high voltage applications which type of 3 phase circuit to be Preferred
(a)        Star
(b)        Delta
(c)        Star or Delta                                                                          
(d)       Neither Star nor Delta
Ans: b
14.       What is the unit of Reactive Power
(a)        KVA
(b)        KW
(c)        HP                                                                                         
(d)       KVAR
Ans:d
15.       R.M.S Value of Half wave rectified  sinusoidal voltage is
(a)        VM/3
(b)        VM/2
(c)        VM/Ö2                                                                                    
(d)       none of these
Ans: b
16.       Current is defined as
(a)        Charge/time
(b)        Time/charge
(c)        power/time                                                                             
(d)       None of these
Ans:a
17.       Active elements are
(a)        Voltage sources only
(b)        Current sources only
(c)        Resistors only
(d)       Both Voltage and Current sources   
Ans: d
18.       In Bilateral Network  the current flows in
(a)        Unidirectional
(b)        Bidirectional
(c)        Rotational
(d)       None of these                                                       
Ans: b
19.       D.C  has
(a)        Constant magnitude
(b)        Variable magnitude
(c)        Fixed Polarities
(d)       Constant magnitude and Fixed Polarities     
Ans: d
20.       In Capacitive circuit, Current flows in the capacitor
(a)        i=C (dv/dt)
(b)        i=V(dc/dt)
(c)        i=C(di/dt)
(d)       i=Ct                                                                                  
Ans: a
21.       Unit of voltage is
(a)        Ampere
(b)        Volt
(c)        Watt
(d)       Volt-ampere                                                             
Ans: b
22.       Peak factor is defined as the ratio of
(a)        Average value to Maximum value
(b)        Maximum value to Average value
(c)        Peak value to R.M.S Value                                                  
(d)        R.M.S Value to Average value
Ans: c
23.       Average value is
(a)        area/period
(b)        period/area
(c)        length/area                                                                
(d)       none of these
Ans: a
24.       Unit of power is
(a)        Ampere
(b)        Volt                                                                              
(c)        Watt
(d)       joules
Ans:c
25.       Unit of apparent  power is
(a)        Ampere
(b)        Volt                                                                                       
(c)        Watt
(d)       Volt-ampere
Ans:d
26.       Unit of energy is
(a)        KWH
(b)        Volt
(c)        Watt                                                                                     
(d)       Volt-ampere
Ans:a
27.       A.C  has
(a)        Constant magnitude
(b)        Variable magnitude
(c)        Fixed Polarities
(d)       Constant magnitude and Fixed Polarities         
Ans: b
28.       Passive  elements are
(a)        Voltage sources only
(b)        Current sources only
(c)        Resistors ,inductors and capacitors
(d)       Both Voltage and Current sources          
 Ans: c
29.       In D.C , inductor acts  as
(a)        Short circuit
(b)        Open circuit
(c)        both (a)&(b)
(d)       none of these           
Ans: a
30.       In Unilateral Network  the current flows in
(a)        Unidirectional
(b)        Bidirectional
(c)        Rotational
(d)       None of these
Ans: a
31.       Workdone is
(a)        F.d
(b)        E/F
(c)        IR
(d)       None of these
Ans: a
32.       Unit of Resistance is
(a)        Ampere
(b)        Volt
(c)        Watt
(d)       ohms                                                                     
    Ans: d
33.       Unit of inductance is
(a)        Ampere
(b)        Volt
(c)        Watt
(d)       henry                                                                      
   Ans: d
34.       Unit of capacitance is
(a)        Ampere
(b)        farad
(c)        Watt
(d)       henry                                                                         
Ans: b
35.       For high current applications which type of 3 phase circuit is Preferred
(a)        Star
(b)        Delta
(c)        Star or Delta                                                                     
(d)       Neither Star nor Delta
Ans: a
36.       For low voltage applications which type of 3 phase circuit to be Preferred
(a)        Star
(b)        Delta
(c)        Star or Delta                                                                   
(d)       Neither Star nor Delta
Ans: a
37.       Unit of charge is
(a)        Ampere
(b)        coulomb
(c)        Watt
(d)       henry                                                                        
Ans: b
38.       EMF is
(a)        Election motion force
(b)        Electrical motion force
(c)        Electro motive  force
(d)       None of these
Ans: c
39.       MMF is
(a)        Magnetic motive force
(b)        Magnetic motion force
(c)        Magneto  motive  force
(d)       None of these
Ans: c
40.       Voltage-Current relationship in inductor element is
(a)        In phase
(b)        90 (lead)
(c)        90 (lag)
(d)       constant                                                                  
Ans: c
41.       Voltage-Current relationship in capacitor element is
(a)        In phase
(b)        90 (lead)
(c)        90 (lag)
(d)       constant                                                                  
  Ans: b
42.       When two inductors are connected in series, equivalent inductance is
(a)        L1+L2
(b)        1/(L1+L2)
(c)        L1.L2
(d)       None of these
Ans: a
43.       When two capacitors are connected in series, equivalent capacitance is
(a)        C1+C2
(b)        1/(C1+C2)
(c)        L1.L2
(d)       (1/c1)+(1/c2)                                                                     
Ans: d
44.       R.M.S Value of full wave rectified  sinusoidal voltage is
(a)        VM/3
(b)        VM/2
(c)        VM/Ö2                                                                               
(d)       none of these
Ans:c
45.       Form factor  of full wave rectified  sinusoidal voltage is
(a)        1.21
(b)        1.11
(c)        4.44                                                                          
(d)       none of these
Ans: b
46.      Power factor for pure inductor
(a)        0(lead)
(b)       0
(c)        0(lag)                                                                      
(d)       none of these
Ans: c
47.       Power factor for pure capacitor
(a)        0(lead)
(b)       0
(c)        0(lag)                                                                       
(d)       none of these
Ans: a
48.       Frequency is defined as
(a)        No of cycles/sec
(b)        time/cycles
(c)       1/cycles
(d)       None of these
Ans: a
49.       In Series resistive circuit,  voltage across each resistor  is
(a)       divided
(b)       constant
(c)       no change
(d)      None of these
Ans: a
50.       In Series resistive circuit  current through each resistor  is
(a)        divided
(b)        same
(c)        0
(d)        None of these
Ans:b

No comments:

Post a Comment