Electrical Circuits 1000+ MCQ with answer for IBPS Clerk

1. Liquids that are good conductors because of ionization are called
A. Electrolytic
B. Bases
C. Acid
D. Electrolytes
Answer : D

2. For maximum power transfera what is the relation between load resistance RL and internal resistance R of the voltage source?
A. RL= 2 r
B. RL= 1.5 r
C. RL= r
D. RL= 3 r
Answer : C

3. The temperature coefficient of resistance of electrolytes is
A. Negative
B. Positive
C. Zero
D. Infinite
Answer : A

4. An impedance given by 90 -45� is a/an ___ impedance.
A. Inductive
B. Conductive
C. Resistive
D. Capacitive
Answer : D

5. For greater accuracya the value of phase angle should be determined from
A. Cos
B. Tan
C. Sin
D. Sec
Answer : B

6. What is the conductance of a circuit having three 10 resistors in parallel?
A. 0.3 S
B. 3.33 S
C. 0.33 S
D. 30 S
Answer : A

7. If voltage across the plates of 2 F capacitor is increased by 4 Va then charge on the plates will
A. Decrease by 2 C
B. Increase by 2 C
C. Decrease by 4 C
D. Increase by 4C
Answer : D

8. What is the reciprocal of capacitance?
A. Reluctance
B. Susceptance
C. Elastance
D. Conductance
Answer : C

9. Capacitance increase with
A. Larger plate area and less distance between plates
B. Larger plate area and greater distance between plates
C. Smaller plate area and less distance between plates
D. Higher values of applied voltage
Answer : A

10. Series resonant circuit is sometimes known as
A. Rejector circuit
B. Acceptor circuit
C. Inductive circuit
D. Capacitive circuit
Answer : B

11. A capacitor opposes change in
A. Voltage
B. Current
C. Voltage and current
D. Neither voltage nor current
Answer : A

12. A capacitor consists of two
A. Conductors only
B. Dielectric only
C. Conductors separated by a dielectric
D. Dielectric separated by a conductor
Answer : C

13. An inductance of 1 mH is
A. 0.001 H
B. 0.01 H
C. 0.0001 H
D. 0.10 H
Answer : A

14. An open inductor has
A. Zero resistance and infinite inductance
B. Infinite resistance and zero inductance
C. Infinite resistance and infinite inductance
D. Zero resistance and zero inductance
Answer : B

15. The power factor of a certain circuit in which the voltage lags behind the current is 80 %. To increase the power to 100 %a it is necessary to add ___ to the circuit.
A. Inductance
B. Capacitance
C. Resistance
D. Impedance
Answer : A

16. How many degrees of phase represents one full cycle?
A.
B.
C.
D.
Answer : A

17. If a capacitor is rated for 200V dca what is its effective ac working voltage?
A. 50 V
B. 100 V
C. 200 V
D. 400 V
Answer : C

18. If the output resistance of a voltage source is 4 a it internal resistance should be
A.
B.
C.
D. Infinite
Answer : A

19. Under the conditions of maximum power transfera a voltage source is delivering a power of 15 W to the load. What is the power generated by the source?
A. 60 W
B. 30 W
C. 15 W
D. 4 W
Answer : B

20. A capacitive load always has a ______ power facto
A. Leading
B. Lagging
C. Zero
D. Unity
Answer : A

21. An inductive circuit of resistance 16.5 and inductance of 0.14 H takes a current of 25 ?. if the frequency is 50 Hza find the supply voltage.
A. 1501 V
B. 1174V
C. 1877V
D. 991 V
Answer : B

22. Which factor does not affect resistance?
A. Length
B. Resistivity
C. Cross-sectional area
D. Mass
Answer : D

23. What is the efficiency under the conditions of maximum power transfer?
A.
B.
C.
D.
Answer : A

24. In dividing or multiplying phasor quantitiesa ___ form is used.
A. Polar
B. Rectangular
C. Trigonometric
D. Exponential
Answer : A

25. What is the rms value of a square wave?
A. Equals its peak value
B. Equals its peak-to-peak value
C. Peak divided by square root of two
D. Peak divided by pi
Answer : A

26. Which of the following capacitors are used only in dc circuits?
A. Mica
B. Ceramic
C. Mylar
D. Electrolytic
Answer : D

27. At what frequency will the current in a series RLCcircuit reach its maximum value for an applied voltage of 15 V with R = 500 a L = 100 H and C= 0.001 F?
A. 503 kHz
B. 403 kHz
C. 603 kHz
D. 303 kHz
Answer : A

28. What determines the magnitude of electric current?
A. The rate at which electrons are produced
B. The type of material used
C. The current carrying capacity of the circuit
D. The rate at which electrons pass a given point
Answer : D

29. What is considered as the most important value of a sine wave?
A. Effective value
B. Peak value
C. Average value
D. Instantaneous value
Answer : A

30. If two complex conjugates are addeda ___ components results.
A. In-phase
B. Quadrature
C. Complex
D. Outof-phase
Answer : A

31. Which of the following has negative temperature coefficient?
A. Carbon
B. Nickel
C. Brass
D. Constantan
Answer : A

32. If three 100-pF capacitors are connected in seriesa then the total capacitance is
A. 300 pF
B. 100 pF
C. 50 pF
D. 33.3 pF
Answer : D

33. When two pure sine waves of the same frequency and the same amplitude which are exactly 180� outof-phase are added togethera the result is
A. A wave with twice the amplitude
B. A wave with half the amplitude
C. Zero signal
D. A wave with twice the frequency
Answer : C

34. What theorem is generally used in the analysis of vacuum tubes?
A. Superposition theorem
B. Millman�s theorem
C. Thevenin�s theorem
D. Norton�s theorem
Answer : C

35. A trimmer is a variable capacitor in which capacitance is varied by changing the
A. Number of plates
B. Dielectric
C. Distance between plates
D. Plate area
Answer : C

36. A capacitor of 0.5 F charged to 220 V is connected across an uncharged 0.5 F capacitor. What is the voltage across each capacitor?
A. 220 V
B. 150 V
C. 110 V
D. 22 V
Answer : C

37. If two equal resistances connected in series across a certain supply are now connected in parallel across the same supplya the power produced will be _____ that of series connection
A. One-half
B. One-fourth
C. Two times
D. Four times
Answer : D

38. Electric energy refers to
A. Volt divided by coulomb
B. Voltampere
C. Volt-coulomb
D. Watt divided by time
Answer : C

39. A three-by-threea series-parallel matrix of resistorsa all having the same ohmic valuea would have a net resistance of
A. One-third the value of a single resistor
B. Three times the value of a single resistor
C. The same value as a single resistor
D. Nine times the value of a single resistor
Answer : C

40. The charge in the capacitor is stored at the
A. Terminals
B. Plates
C. Dielectric
D. Air
Answer : B

41. What is the reciprocal of quality factor?
A. Power factor
B. Reactive factor
C. Dissipation factor
D. 1/Q factor
Answer : C

42. What is the total resistance of a two equal valued resistors in series?
A. The difference of both
B. The product of both
C. Twice as one
D. The sum of their reciprocals
Answer : C

43. The result of rust in electrical (wire) connection is
A. Inductance
B. Conductance
C. Impedance
D. Resistance
Answer : D

44. What is the cross-sectional are of a conductor whose diameter is 0.001 inch?
A. One micron
B. One angstrom
C. One steradian
D. One circular mil
Answer : D

45. When voltage is applied across a ceramic dielectric the electrostatic field p roduced is 50 times greater than air dielectric. The dielectric constant of ceramic therefore is
A.
B.
C.
D.
Answer : A

46. Which of the following dielectric materials makes the lowest-capacitance capacitor?
A. Paper
B. Mica
C. Air
D. Electrolyte
Answer : C

47. The capacitor opposes any change in voltage across it by
A. Passing a voltage proportional to the rate of change of current
B. Acting as a short circuit at time equal to zero
C. Passing a current proportional to the rate of change of voltage
D. Acting as a short circuit at time equal to infinity
Answer : C

48. Which of the following is not a factor affecting dielectric strength?
A. Mass
B. Moisture content
C. Temperature
D. Thickness
Answer : A

49. In a series circuit with unequal resistances the
A. Highest R has the highest V
B. Lowest R has the highest V
C. Lowest R has the highest I
D. Highest R has the highest I
Answer : A

50. The presence of an electric current is made known by
A. Electric shock
B. Effects produced
C. Magnetic shock
D. Flashing
Answer : B