RRB JE - Electrical Circuits 1000+ MCQ [Solved] PDF Download

1. A term used to express the amount of electrical energy stored in electrostatic field.
A. Joules
B. Coulombs
C. Watts
D. Electron-volt
Answer : A

2. Which of the following is a way of decreasing mutual inductance?
A. Moving the coils closer
B. Moving the coils apart
C. Decreasing the number of turns of either coil
D. Increasing the number of turns of either coil
Answer : B

3. 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

4. Which of the following is a disadvantage of a wire-wound resistor?
A. It has reactance in radio-frequency circuits
B. It cannot handle much power
C. It draws a large amount of current
D. It cannot handle high voltage
Answer : A

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

6. 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

7. Rationalizing the denominator of a complex number means
A. Eliminating the j component in the denominator
B. Adding j component in the denominator
C. Eliminating the j component in the numerator
D. Adding j component in the numerator
Answer : A

8. In calculating maximum instantaneous power ___ voltage or current is used.
A. Peak
B. Average
C. Rms
D. Instantaneous
Answer : A

9. In an ac circuit with a resistive branch and an inductive branch in parallela the
A. Voltage across the inductance leads the voltage across the resistance by 90°
B. Resistive branch current is 90° out of phase with the inductive branch current
C. Resistive and inductive branch currents have the same phase
D. Resistive and inductive branch currents are 180° outof-phase
Answer : B

10. 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

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

12. Points to be considered in choosing a capacitor
A. Working voltage
B. Type of dielectric
C. Capacitance
D. All of the above
Answer : D

13. For a triangular and sawtooth waveform the rms voltage or current equals
A. 0.707times peak value
B. 0.577 times peak value
C. 0.577times average value
D. 0.707times rms value
Answer : B

14. If an emf in circuit A produces a current in circuit Ba then the same emf in circuit Bproduces the same current in circuit ? this theorem is known as
A. Maximum power transfer theorem
B. Millman�s theorem
C. Reciprocity theorem
D. Norton�s theorem
Answer : C

15. A capacitor is used to
A. Block dc current
B. Pass dc current
C. Open voltage source
D. Short the voltage source
Answer : A

16. Norton�s theorem is what form of an ac equivalent circuit?
A. Voltage
B. Current
C. Both voltage and current
D. Neither voltage nor current
Answer : B

17. When current and voltage arte in phase in an ac circuita the ___ is equal to zero.
A. Resistance
B. Reactance
C. Inductance
D. Capacitance
Answer : B

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

19. The farad is not equivalent to which of the following combination of units
A. CV2
B. C2/J
C. C/V
D. J/V2
Answer : A

20. 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

21. In Norton�s theorema the short circuit current is obtained by
A. Opening the load terminals
B. Shorting the load terminals
C. Opening the voltage source
D. Shorting the voltage source
Answer : B

22. Which of the following elements is active?
A. Resistor
B. Inductor
C. Capacitor
D. Ideal voltage source
Answer : D

23. 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

24. 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

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

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

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

28. 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

29. In an inductive coila the rate of rise of current is maximum
A. Near the final maximum value of current
B. At midvalue of current
C. At half-power points
D. After one time constant
Answer : A

30. When the power factor of a circuit is zeroa
A. Power absorbed is maximum
B. Power absorbed is minimum
C. Power absorbed is zero
D. The impedance is minimum
Answer : C

31. What maximum voltage can be applied across the capacitor of time?
A. Working voltage
B. Surge voltage
C. Stray voltage
D. Peak voltage
Answer : B

32. Which of the following is the most popular waveform?
A. Sinusoidal
B. Square wave
C. Triangular
D. Sawtooth
Answer : A

33. A rheostat is a form of
A. Variable resistor
B. Variable capacitor
C. Potentiometer
D. Thermocouple
Answer : A

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

35. The unit of elastance is
A. Farad
B. Daraf
C. Siemen
D. Henry
Answer : B

36. In a complex resistance-reactance planea XLis represented
A. By an axis opposite the R axis
B. By an axis perpendicular to the XC axis
C. By an axis opposite the XCaxis
D. By an axis parallel to the R axis
Answer : C

37. The maximum power transfer theorem is used in
A. Power system
B. Electronic system
C. Refrigeration
D. Air conditioning
Answer : B

38. In an RL series circuita
A. Current lags voltage by less than 90�
B. Current lags voltage by 180�
C. Current lags voltage by 90�
D. Current leads voltage by 90�
Answer : A

39. What refers to the lowest voltage across any insulator that can cause current flow?
A. Conduction voltage
B. Critical voltage
C. Breakdown voltage
D. Voltage capacity
Answer : C

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

41. The arc across a switch when it open an RL circuit is a result of the
A. Large self-induced voltage across L
B. Long time constant
C. Low resistance of the open switch
D. Surge of resistance
Answer : A

42. A switch designed to have low capacitance between its terminal when open.
A. LOCAP switch
B. AntiLOCAP switch
C. Anticapacitance switch
D. Capacitance switch
Answer : C

43. VL= VCin a series RLCcircuit when
A. The value of the impedance is minimum
B. The power factor is zero
C. The current leads the total voltage by 90�
D. The total voltage is zero
Answer : A

44. What dielectric is generally employed by a variable capacitor?
A. Mica
B. Air
C. Electrolyte
D. Ceramic
Answer : B

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

46. What is the hot resistance of a 100 Wa 220 V incandescent lamp?
A.
B.
C.
D.
Answer : C

47. The reciprocal of a complex number is
A. A complex number
B. A real number
C. An imaginary number
D. A whole number
Answer : A

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

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

50. The ratio between the active power and the apparent power of a load in an ac circuit is called
A. Quality factor
B. Power factor
C. Power ratio
D. Power reactive
Answer : B