1000+ Electrical Circuits Multiple Choice Question Answer [Solved]

1. 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

2. Which of the following dielectric materials makes the highest-capacitance capacitor?
A. Air
B. Barium-strontium titanite
C. Mica
D. Electrolyte
Answer : B

3. Loop currents should be assumed to flow in which direction
A. Straight
B. Clockwise
C. Counter-clockwise
D. Either B or C arbitrarily selected
Answer : D

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

5. What fusion of elements is without chemical action between them?
A. Mixture
B. Compound
C. Alloy
D. Ionization
Answer : C

6. 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

7. When two in-phase sine waves that have identical frequency and amplitude are added togethera then the result is a sine wave with ___ the amplitude of either.
A. Half
B. Twice
C. Four times
D. One-fourth
Answer : B

8. Which of the following does not refer to electrical energy?
A. Volt-ampere
B. Joule
C. Watt-second
D. Volt-coulomb
Answer : A

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

10. In an ac circuita the power dissipated as heat depends on
A. Impedance
B. Capacitive reactance
C. Resistance
D. Inductive reactance
Answer : C

11. 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

12. An intermittent and non-symmetrical alternating current like that obtained from the secondary winding of an induction coil
A. Faradic current
B. Transient ac current
C. Inductive current
D. Capacitive current
Answer : A

13. The ratio between the reactive power and the apparent power of an ac load is called
A. Quality factor
B. Power factor
C. Power ratio
D. Reactive power
Answer : D

14. The Q-factor of a parallel resonant circuit is also known as
A. Voltage magnification factor
B. Current magnification factor
C. Gain magnification factor
D. Resonance magnification factor
Answer : B

15. What is the total effective capacitance of two 0.25 F capacitors connected in series?
A. 0.125 F
B. 1.25 F
C. 0.50 F
D. 2.5 if
Answer : A

16. The factor 0.707for converting peak to rms applies only to
A. Square waves
B. Triangle waves
C. Sawtooth waves
D. Sine waves
Answer : D

17. Refers to the outward-curving distortion of the lines of force near the edges of two parallel metal plates that form a capacitor.
A. Skin effect
B. Night effect
C. Edge effect
D. Hall effect
Answer : C

18. 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

19. For series capacitorsa total charge is
A. The sum of individual charges
B. Equal to the charge of either capacitors
C. Equal to the product of the charges
D. The quotient of the charges
Answer : B

20. 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

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

22. Which of the following has a positive temperature coefficient?
A. Mica
B. Manganin
C. Silicon
D. Carbon
Answer : B

23. 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

24. 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

25. 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

26. A 5 F capacitor charge to 5V has a stored charge equal to
A. 1 c
B. 5 c
C. 25 C
D. 200 c
Answer : C

27. 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

28. With double the number of turns by the same length and areaa the inductance is
A. The same
B. Doubled
C. Quartered
D. Quadrupled
Answer : D

29. The Q-factor of a series resonant circuit is also known as
A. Current magnification factor
B. Voltage magnification factor
C. Load factor
D. Leakage factor
Answer : B

30. What is the most common non-sinusoidal waveform?
A. Square wave
B. Triangular wave
C. Trapezoidal wave
D. Sawtooth wave
Answer : A

31. 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

32. 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

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

34. What is the complex impedance of a circuit with an absolute resistance of 300 ?
A. 0 + j 300
B. 300 + j 90
C. 0 ± j 300
D. 300 +j 0
Answer : D

35. 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

36. Which one of the following elements serves as a protection against overload?
A. Fuse
B. Switch
C. Resistor
D. Relay
Answer : A

37. Which of the following is the statement of Ohm�s law?
A. Electric current is directly proportional to both voltage and resistance
B. Electric current varies directly as the voltage and inversely as the resistance
C. Electrical power is directly proportional to the resistance and inversely as the current squared
D. Electrical power is directly proportional to both voltage squared and the resistance
Answer : B

38. The ratio of maximum value to the effective value of an alternating quantity is called
A. Form factor
B. Peak factor
C. Dynamic factor
D. Leakage factor
Answer : B

39. A capacitance of 0.05 F equals
A. 0.05 x 106F
B. 0.05 x 10-6F
C. 0.05 x 10-12F
D. 0.05 x 1012F
Answer : B

40. The reactance curve is a plot of frequency versus _____ for a series RLCcircuit
A. Current
B. Voltage
C. Gain
D. Impedance
Answer : A

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

42. 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

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

44. In a resonant circuita if Q ? 10 resonant frequency _______ bandwidth.
A. Bisects
B. Exceeds
C. Is less than
D. Is equal to
Answer : A

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

46. 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

47. When two unequal values of resistors are connected in parallel across a dc sourcea greater current flows through the
A. Higher resistance
B. Lower resistance
C. Higher wattage resistance
D. Lower wattage resistance
Answer : B

48. The graph between an alternating quantity and time is called
A. Sine wave
B. Curve
C. Waveform
D. A plot
Answer : C

49. 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

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