RBI Assistant - Electrical Circuits 1000+ MCQ [Solved] PDF Download

1. 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

2. In a parallel bank with unequal branch resistances
A. The highest R has the highest I
B. The lowest R has the highest V
C. The lowest R has the highest V
D. The highest R has the highest V
Answer : B

3. 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

4. The second strip of an electronic resistor color-code represents
A. The multiplier
B. The second digit of the value
C. The temperature
D. The tolerance
Answer : B

5. The impedance in the study of electronics is represented by resistan
A. Inductance
B. Capacitance
C. Inductance and capacitance
D. Reactance
Answer : D

6. 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

7. A series-parallel combination of identical resistors will
A. Increase the power rating compared with one resistor alone
B. Increase the voltage rating compared with one resistor alone
C. Reduce the voltage rating compared with resistor alone
D. Result in an expensive circuit
Answer : A

8. 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

9. In a circuita an active element is one which
A. Supplies energy
B. Receives energy
C. Both supplies and receives energy
D. Amplifies signal
Answer : A

10. When two coils of identical reactance are in parallel without mutual inductancea the reactance of the combination is ___ the reactance of each coil.
A. One half
B. Twice
C. Four times
D. One fourth
Answer : A

11. When capacitors are connected in seriesa the total capacitance is
A. Smaller than the smallest capacitor
B. Smaller than the largest capacitor
C. Greater than any of the capacitor
D. Greater than the largest capacitor
Answer : A

12. 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

13. Which of the following describes the action of a capacitor?
A. Stores electrical energy
B. Opposes changes in current flow
C. Creates a dc resistance
D. Converts ac to dc
Answer : A

14. Which of the following conditions is not true for a series RLCcircuit at resonance?
A. Z = jXL
B. XL= XC
C. The power factor is one
D. The magnitude of Z is
Answer : A

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

16. If a certain circuit has a current that is lagging the voltage by 45�a then it displays
A. Pure inductive reactance
B. Resistance and capacitance reactance
C. Resistance and inductive reactance
D. Pure capacitive reactance
Answer : C

17. What is the form factor of a triangular wave?
A.
B.
C.
D.
Answer : A

18. The internal resistance of an ideal current source is
A. Infinite
B. Zero
C. Equal to the load resistance
D. To be determined
Answer : A

19. The ratio of the flux density to the electric field intensity in the dielectric is called
A. Permittivity
B. Field intensity
C. Permeability
D. Elasticity
Answer : A

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

21. 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

22. Which statement is true?
A. A series resonant circuit is of high impedance
B. A parallel resonant circuit is of low impedance
C. A series resonant circuit is inductive if it operates at a frequency higher than the resonant frequency
D. A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency
Answer : C

23. 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

24. What is a rotating vector whose projection can represent either current or voltage in an ac circuit?
A. Polar diagram
B. Scalar quantity
C. Velocity
D. Phasor
Answer : D

25. 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

26. At parallel resonancea the currents flowing through L and C are
A. Infinite
B. Zero
C. Unequal
D. Equal
Answer : D

27. 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

28. The voltage lags the current by cycle in a
A. Purely resistive circuit
B. Purely inductive circuit
C. Purely capacitive circuit
D. Circuit containing resistancea capacitance and inductance
Answer : C

29. Delta to wye or wye to delta transformation technique is applied to a ___ network.
A. One-terminal
B. Two-terminal
C. Three-terminal
D. Complex
Answer : C

30. 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

31. The temperature-resistance coefficient of pure gold is
A.
B.
C.
D.
Answer : A

32. What is the other name of relative permittivity?
A. Dielectric strength
B. Potential gradient
C. Breakdown voltage
D. Specific inductance capacity
Answer : D

33. Which of the following is not a factor affecting capacitance oor?
A. Area of plates
B. Number of plates
C. Distance between plates
D. Dielectric material used
Answer : B

34. Which of the following is also known as antiresonant circuit?
A. Parallel resonant circuit
B. Series resonant circuit
C. Tuned circuit
D. Tank circuit
Answer : A

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

36. The curve between current and frequency is termed as
A. Voltage curve
B. Gain curve
C. Power curve
D. Resonance curve
Answer : D

37. 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

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

39. 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

40. According to Gauss theorema flux can be equated to
A. Charge
B. Field intensity
C. Current
D. Voltage
Answer : A

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

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

43. The ___ of an alternating quantity is defined as the fractional part of a period or cycle through which the quantity has advanced from selected origin.
A. Phase
B. Frequency
C. Amplitude
D. Waveform
Answer : A

44. In an ac circuit with XL and R in seriesa the
A. Voltages across R and XL are in phase
B. Voltage across R lags the voltage across XLby 90°
C. Voltages across R and XL are 180° outof-phase
D. Voltage across R leads the voltage across XLby 90°
Answer : B

45. The rms value of a triangular or sawtooth waveform is ___ tim value.
A.
B.
C.
D.
Answer : A

46. If a multiplate capacitor has 10 platesa each of area 10 cm2a then
A. 10 capacitors will be in parallel
B. 10 capacitors will be in series
C. 9 capacitors will be in parallel
D. 9 capacitors will be in series
Answer : C

47. 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

48. The capacitance of a capacitor is ___ relative permittivity.
A. Directly proportional to
B. Inversely proportional to
C. Equal to
D. Inversely proportional to the square of
Answer : A

49. Which of the statements below is not true?
A. Current source is an active element
B. Resistor is a linear element
C. Voltage source is a passive element
D. Diode is a non-linear element
Answer : C

50. 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