Basic electrical mcq

1)what is the effects of capacitor.

a)it opposes any change in the amount of voltage

b) electrical energy  is stored in the capacitor in the form of electrostatic field.

c) voltage is lagged behind the current by a quarter cycle. 

d) all of the above 

ANS: all of the above

2) point to be considered in choosing a capacitor .

a) working voltage 

b)type of dielectric 

 

c) capacitance

d) all of the above

ANS : all of the above

3) which is the following does not affects resistance .

a) resistivity 

b) cross section area 

c) mass

d) length

ANS : mass

4) the reason why electrical appliance are connected in parallel.

a) it is simple circuit 

b) this makes the operation of appliances independent with each other 

c) this results in power consumption

d) all of the above 

ANS:  this makes the operation of appliances independent with each other 

5) what determines the direction of induced emf in a conductor or coil.

a) flemings left hand rule 

b)flemings right hand rule

c)cork screw rule 

d) amperes circuit law 

ANS: flemings left hand rule 

6) permeability is same as

a) magnetic conductivity 

b) electric conductivity 

c) electric susceptibility

d)  magnetic susceptibility

ANS: magnetic conductivity

7) the value of temperature coefficient is depend upon

a) the volume of the material

b) the length of material 

c) the cross sectional area of the material

d) the nature of material and temperature 

ANS : the nature of material and temperature 

8) the charge in the capacitor is stored at the 

a) air 

b) terminal 

c) plates 

d) dielectric 

ANS : plates

9) in an ac circuit with XL and R in series , the 

a) voltage across R and XL are in phase 

b)  voltage across R lags the voltage across  XL by 90 

 c) voltage across R and XL are 180 out of phase  

d) voltage across R leads the voltage across XL by 90

 ANS :voltage across R lags the voltage across  XL by 90 

10) which component oppose voltage change

a) Resistor

b) inductor 

c) capacitor 

d) all of the above 

ANS : capacitor 

 

11) which component oppose  changing current 

a) Resistor

b) inductor 

c) capacitor 

d) all of the above 

ANS : inductor

12) at parallel resonance , the current flowing through L and C are 

a) equal

b) unequal

c) infinite 

d) zero

ANS: equal

13) in pure capacitive  circuit

a) current leads voltage by 90 

b)  current lags voltage by 90 

 c) current leads voltage by 180

d) current lags voltage by 180 

ANS: current leads voltage by 90 

14) in pure inductive  circuit

a) current leads voltage by 90 

b)  current lags voltage by 90 

 c) current leads voltage by 180

d) current lags voltage by 180 

ANS: current lags voltage by 90 

15) in pure resistive  circuit

a) current leads voltage by 90 

b)  current lags voltage by 90 

 c) current leads voltage by 180

d) current and voltage are same phase 

ANS: current and voltage are same phase

16) which of the statements below is not true 

a) current source is an active element 

b) voltage source is a passive element 

c) resistor is a linear element 

d) diode is a non-linear element 

ANS : voltage source is a passive element 

17) which of the following element is active 

a) resistor 

b)  ideal current source 

c) inductor 

d) capacitor

ANS : ideal current source

18) which of the following element is passive 

a) ideal current source 

b) ideal voltage source 

c) resistor 

d) all of the above 

ANS : resistor  

19) the Q - factor of a series resonant circuit also know as 

a) current magnification factor 

b) voltage magnification factor 

c) load factor 

d) leakage factor 

ANS: Voltage magnification factor 

20) the Q - factor of a parallel resonant circuit also know as 

a) current magnification factor 

b) voltage magnification factor 

c) load factor 

d) leakage factor 

ANS: current  magnification factor

21) series resonant circuit is also know as 

a)Acceptor circuit 

b) rejector circuit 

c) capacitive circuit 

d) inductive circuit 

ANS : Acceptor circuit 

 

22) parallel resonant circuit is also know as 

a)Acceptor circuit 

b) rejector circuit 

c) capacitive circuit 

d) inductive circuit 

ANS : rejector  circuit 

23) when two unequal value of resistor are connected in parallel across a dc source greater current flows through the 

a)  higher resistance 

b) lower resistance 

c) a and b both equal 

d) none of the above 

ANS : lower resistance 

24) A real current source has 

a) small internal resistance 

b) large internal resistance 

c) zero internal resistance 

d) infinite internal resistance 

ANS : large internal resistance 

25) a capacitor is used to 

a) block dc current 

b) pass dc current 

c) open voltage source 

d ) short the voltage source

ANS: block dc current 

26 ) a inductor is used to 

b) pass dc current 

c) open voltage source 

d ) short the voltage source

ANS: pass  dc current 

note : in a dc source the inductor act as the short circuit and capacitor act as open circuit . 

27) resistivity of  a wire depend upon the

a) length                b) material          

c) cross section area   d) none of the above

ANS: Material 

28) Resistance of a wire directly proportional to the

a) length                                 b) material           c) cross section area                                        d) none of the above

ANS: Length 

29) resistance of a wire is X ohms. the wire is stretched to double its length , then its resistance in ohms is

a) X/2                  b) 2X                        c)X/4                                   d) 4X

ANS:4X

30) kirchhoffs second law(KVL) is based on law of conservation of 

a) charge                               b) energy                c) momentum                      d) mass

ANS: Energy 

31) kirchhoffs first  law (KCL) is based on law of conservation of 

a) charge                               b) energy                c) momentum                      d) mass

ANS: Charge 

32) the unit of electrical conductivity is 

a) mho/m                        b)mho/m²                      c) ohm/m                        d)ohm/m²

ANS:Mho/m

33) the unit of conductance is 

a) mho/m                b)mho                                c) ohm/m                 d) per ohm

ANs:Mho

34) a fuse is always connected in a circuit is 

     a) series                                      b) parallel         c) either series or parallel                                 d) none of the above

ANS: series

35) the ratting of fuse wire is expressed in terms of

a) ohms                                 b) mhos                c) amperes                           d) watts

ANS:Amperes

36)which is following material is not used as fuse material

a) silver                    b) copper                            c) aluminium          d) carbon

ANS: Carbon

37) the element of electric heater is made of 

a) copper             b) steel                                    c) carbon             d)nichrome

ANS: Nichrome 

38) in a series connection of  resistor which quantity  always same

a)current                    b) voltage                      c)  current and voltage both                          d) all of the above

 

ANS: current 

39) in a parallel connection of  resistor which quantity  always same

a)current                    b) voltage                      c)  current and voltage both                          d) all of the above

ANS: VOLTAGE 

40) ampere second could be the unit of 

a) power           b) energy                    c)charge            d)conductance

ANS: Charge 

41) which of the  following  is not same as watt

a) joule / sec                     b) amperes. volt   c) (amperes)². volt        d)amperes/ volt  

ANS: Amperes/ volt

42) an a ideal current source has 

a)high  internal resistance                            b) low internal resistance                              c) zero internal resistance                              d) none of  the above

ANS: High internal resistance 

43) an a ideal voltage source has 

a)high  internal resistance                              b) low internal resistance                              c)   a and b both                                                    d) none of the above

ANS:Low internal resistance 

44)  series resonance  occurs when 

a) XL = R                 b)Z=R           

 C) XL = Xc           d) all of the above

ANS:XL=Xc

45)the earth resistance can be measured by 

a) fall of  potential method 

b) using an  earth tester

c) ducter ohmmeter method

d) a and b both

ANS: a and b both

46) electrostatic voltmeter are suitable for 

a) dc only 

b) ac only 

C) ac and dc both 

d) none of these 

ANS: ac and dc both

47) the ohmmeter is basically 

a) ammeter

b) voltmeter

c) multimeter

d) all of above

ANS: ammeter

48) a thermo couple instrument can be used for the measurement  of 

a) dc current only 

b) ac current only

c) both ac and dc 

d) none of these

ANS: both ac and dc

49) no eddy current and hysteresis losses occurs in 

a) moving iron type instrument 

b) PMMC instrument 

c) electro dynamo meter  instrument 

d) electrostatic instrument

ANS: electrostatic instrument

 

50) the resistance can be measured most accurately by

a) multimeter 

b) megger 

c) voltmeter - ammeter method 

d) bridge method

ANS: bridge method

51) the oscilloscope indicates

a) peak to peak value of voltage

b) RMS value 

c) DC value of voltage 

d) average value 

ANS: peak to peak value of voltage

52) which of  the following meter has a linear scale 

a) thermocouple 

b) moving iron meter

c) moving coil meter

d) hot wire meter 

ANS: moving coil meter 

53) which of the cheapest instrument for dc measurement 

a) moving iron 

b) PMMC

c) hot wire

d) electro- dynamo

ANS; moving iron

54) which of the following instruments can be measured AC current  only 

a) moving iron ammeter 

b) moving iron voltmeter

c) induction type ammeter 

d) permanent magnet type ammeter

ANS: induction type ammeter

55) which type of instrument  are digital energy meter and amper hour meter

a) recording type 

b) indicating type 

c) integrating type 

d) all of the above

ANS:  integrating type 

56) the forced or torque which bring the needle in motion is called 

a) deflecting torque

b) controlling torque

c) damping torque 

d) none of the above 

ANS: deflecting torque

57) PMMC type instrument are used to measurement 

a) ac value only

b) dc value only

c) ac and dc both

d) none of the above

ANS: dc value only

58) Moving iron type instrument are generally  used to measurement  

 a) ac value 

b) dc value 

c) ac and dc both

d) none of the above

ANS: ac value 

59) the instrument in which deflecting  torque is produced due to permanent magnet is called

a) moving iron type 

b) PMMC type 

c) a and b both 

d) none of these

ANS: PMMC type

60)  the instrument in which deflecting  torque is produced due to electro magnet is called

a) moving iron type 

b) PMMC type 

c) a and b both 

d) none of these

ANS: moving iron type

61) wheat stone bridge method used to measurement of 

a) low resistance 

b) medium resistance

c) high resistance 

d) all of the above

ANS: medium resistance

62) kelvin double bridge method used to measurement of 

a) low resistance 

b) medium resistance

c) high resistance 

d) all of the above

ANS: low resistance

63) megger used to measurement of 

a) low resistance 

b) medium resistance

c) high resistance 

d) all of the above

ANS: high resistance

64) the instrument used to measured insulation resistance or high resistance is called

a) voltmeter 

b) ammeter 

c) ohmmeter

d) megger

ANS: Megger

65) schering   bridge method used to measurement of 

a) resistance 

b) voltage 

c) inductance

d) capacitance

ANS:  capacitance

66)  anderson bridge method used to measurement of 

a) resistance 

b) voltage 

c) inductance

d) capacitance

ANS: inductance

67) which of the measuring instrument are used ac and dc both

a) PMMC

b) moving iron 

c) electro dynamo 

d) all of the above

68) which of the force or torque bring the needle  in its proper position very quickly 

a) damping torque 

b) controlling torque

c ) deflecting torque

d) none of these

ANS: damping torque

69) which of the force or torque control the movement of pointer 

a) damping torque 

b) controlling torque

c ) deflecting torque

d) none of these

ANS: controlling  torque