Electrical Circuits 1000+ MCQ with answer for SBI Clerk

1. What is the half-power bandwidth of a parallel resonant circuit which has a resonant frequency of 3.6 MHz and Q of 218?
A. 1.65 kHz
B. 16.5 MHz
C. 16.5 kHz
D. 165 kHz
Answer : C

2. If three 9 mH inductors are connected in parallel without mutual inductance then the total i nductance is
A. 3 mH
B. 9 mH
C. 27mH
D. 18 mH
Answer : A

3. For a series circuita the higher the quality factor
A. The greater the bandwidth
B. The narrower the passband
C. The broader the resonance curve
D. The wider the passband
Answer : B

4. When two complex conjugates are subtracteda the result is a
A. Quadrature component only
B. Complex component
C. In-phase component
D. Real component
Answer : A

5. Which of the following is a preferred resistor value?
A.
B.
C. 43a000
D. 54a321
Answer : B

6. 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

7. The mutual inductance between two coils is ___ the reluctance of magnetic path.
A. Directly proportional to
B. Inversely proportional to
C. Independent to
D. Equal to
Answer : B

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

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

10. Which of the following is neither a basic physical law nor deliverable from one?
A. Ohm�s law
B. Coulomb�s law
C. Kirchhoff�s first law
D. Kirchhoff�s second law
Answer : A

11. In a pure capacitancea
A. Current leads voltage by 90�
B. Current leads voltage by 180�
C. Current lags voltage by 90�
D. Current lags voltage by 180�
Answer : A

12. In a series RLCcircuit
A. The current lags VLby 90�
B. The current leads VLby 90�
C. XL leads Xcby 90�
D. Z = jXL at resonance
Answer : A

13. The charging of a capacitor through a resistance follows what law?
A. Linear law
B. Hyperbolic law
C. Inverse-square law
D. Exponential law
Answer : D

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

15. A capacitance of 6 ��F means
A. 6 pF
B. 6 nF
C. 6 fF
D. 6 aF
Answer : A

16. A wire of one kilometre length has a resistance of 20 . If the length is halveda then the new resistance is ___ the original resistance.
A. Half
B. Twice
C. One-fourth
D. Three times
Answer : A

17. For a series ACcircuita ___ is not used as a reference phasor.
A. Voltage
B. Impedance
C. Current
D. Conductance
Answer : A

18. 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

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

20. In a circuita a passive element is one which
A. Supplies energy
B. Receives energy
C. Both supplies and receives energy
D. Attenuates signal
Answer : B

21. For multi-plate capacitora capacitance is proportional to
A. Number of plates less one(n ± 1)
B. Number of plates plus one(n + 1)
C. Number of plates less two(n - 2)
D. Number of plates (n)
Answer : A

22. An ac series circuit is composed of a resistance of 20 a inductive reactance of 40 a and a capacitive reactance of 15 . If a current of 1 ampere is flowinga what is the applied voltage
A. 320 V
B. 32 V
C. 220 V
D. 22 V
Answer : B

23. A series RLCcircuit has a ______ power factor at its half-power points
A. Unity
B. Leading
C. Lagging
D. Either B or C
Answer : D

24. 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

25. 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

26. The potential gradient in a cable is maximum in
A. Conductor
B. Outer sheath
C. Insulation
D. Uniformly all over
Answer : A

27. An alloy composed of 84 % coppera 12 % manganese and 4 % nickel.
A. Manganin
B. Constantan
C. Nichrome
D. German silver wire
Answer : A

28. Which of the following is a common material used in wire-wound resistors?
A. Manganin
B. Carbon
C. Bronze
D. German silver wire
Answer : A

29. The symbol Q refers to
A. Resonance quotient
B. Quality factor
C. Power quotient
D. Qualification test
Answer : B

30. 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

31. Transient period is considered over after
A.
B.
C.
D.
Answer : A

32. Property of an electric circuit that dissipates electric energy
A. Reactance
B. Impedance
C. Resistance
D. Conductance
Answer : C

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

34. If two resistances of 9 and 6 are connected in parallela the total resistance is
A.
B.
C.
D.
Answer : D

35. 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

36. If resonant frequency is 10 kHz and quality factor is 50a then
A. Bandwidth is 200 Hz
B. XL= is 50a000
C. R is 50
D. XC= is 50a000
Answer : A

37. The charging of a capacitor through a resistance obeys
A. Exponential law
B. Logarithmic law
C. Linear law
D. Square law
Answer : A

38. The ratio of W/VA in an ac circuit means
A. Power factor
B. Reactive factor
C. Quality factor
D. Load factor
Answer : A

39. Resistor with colored bands in the body
A. Wire-wound resistor
B. Carbon-composition resistor
C. Potentiometer
D. Rheostat
Answer : B

40. What is the temperature coefficient of the resistance Eureka?
A. Infinity
B. Negative
C. Almost zero
D. Positive
Answer : C

41. 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

42. Metal tin becomes superconductor at approximately
A. 6 K
B. 3.7 K
C. 5 K
D. 4.7K
Answer : B

43. The reason why electrical appliances are connected in parallel.
A. It is a simple circuit
B. This makes the operation of appliances independent with each other
C. This results in reduced power consumption
D. All of the above
Answer : B

44. It is impossible to change the voltage across a capacitor instantlya as this would produce ___ current.
A. Infinite
B. Zero
C. Low
D. High
Answer : A

45. And ideal current source has an internal conductance of _____ siem
A. Infinite
B. One
C. Zero
D. One million
Answer : C

46. 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

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

48. 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

49. What is the specific resistance of a pure germanium?
A. 55 -cm
B. 55 -m
C. 55 -mm
D. 55 k -m
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