Electrical Circuits 1000+ MCQ with answer for SSC MTS

1. A series RLCcircuit consists of a 10 resistor in series with L = 10 Ha and C= 100 F. Determine a new value of Ia for which the resonant frequency is one ±half the original value.
A. 40 H
B. 40 mH
C. 40 pH
D. 40 nH
Answer : A

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

3. 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

4. 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

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

6. 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

7. 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

8. 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

9. If one resistance in a series connection is opena then
A. The current is zero in all the other resistances
B. The current is maximum in all the other resistances
C. The voltage is zero across the open resistance
D. The voltage is infinite across the open resistance
Answer : A

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

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

12. The current is ____ times the maximum current at half-power points of a resonance curve.
A.
B.
C.
D.
Answer : A

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

14. 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

15. 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

16. Two complex numbers or phasors are said to be conjugate if they
A. Differ only in the algebraic sign of their quadratic components
B. Differ only in the algebraic sign of their real components
C. Are equal in their real and quadrature components including alge
D. Are equal in their real components but differ in their quadrature components i ncluding algebraic signs.
Answer : A

17. 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

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

19. Another term for superconductor.
A. Generic conductor
B. Ultraconductor
C. Cryotron
D. Cryogenic conductor
Answer : D

20. 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

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

22. Which of the following capacitors has the highest cost per F?
A. Plastic
B. Air
C. Mica
D. Electrolytic
Answer : D

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

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

25. 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

26. 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

27. Tungsten filament of bulbs has a hot resistance higher than its cold resistance due to its temperature coefficient which is
A. Positive
B. Negative
C. Zero
D. Infinite
Answer : A

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

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

30. 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

31. 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

32. 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

33. What is the time constant for L of 240 mH in series with R of 20 ?
A. 12 ms
B. 4.8 s
C. 83.3 s
D. 12 s
Answer : A

34. The hot resistance of an incandescent lamp is about ___ times its cold resistance.
A.
B.
C.
D.
Answer : A

35. 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

36. 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

37. Voltage resonance means
A. Series resonance
B. Parallel resonance
C. Current magnification
D. Gain magnification
Answer : A

38. In a series RLCcircuit
A. Increasing the frequency decreases the resistance
B. Increasing the frequency increases the resistance
C. Both XLand XCchange as frequency changes
D. Impedance will always decrease
Answer : C

39. Effects of capacitance
A. It opposes any change in the amount of voltage
B. Voltage is lagged behind the current by a quarter cycle
C. Electric energy is stored in the capacitor in the form of electrostatic field
D. All of the above
Answer : D

40. 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

41. 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

42. When the temperature of copper wire is increased its resistance is
A. Increased
B. Decreased
C. Constant
D. Zero
Answer : A

43. The area of capacitor plates increases two timesa then its capacitance
A. Increases two times
B. Increases four times
C. Decreases two times
D. Decreases four times
Answer : A

44. The temperature-resistance coefficient of pure gold is
A.
B.
C.
D.
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. In dividing or multiplying phasor quantitiesa ___ form is used.
A. Polar
B. Rectangular
C. Trigonometric
D. Exponential
Answer : A

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

48. The usual load of a dc circuit is a/an
A. Resistor
B. Capacitor
C. Inductor
D. Both inductor and capacitor
Answer : A

49. 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

50. The value of temperature coefficient ( ) is dependent upon
A. The nature of material and temperature
B. The length of material
C. The cross-sectional area of the material
D. The volume of the material
Answer : A