1000+ Electrical Circuits MCQ for SSC JHT [Solved]

1. When the net reactance in a series coil-capacitor circuit is zero at frequency fa the nature of its reactance of frequency 2f is
A. Inductive
B. Capacitive
C. Resistive
D. Infinite
Answer : A

2. 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

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. What capacitance exists not through design but simply because two conducting surfaces are relatively close to each other?
A. Surge
B. Stray
C. Natural
D. Normal
Answer : B

5. 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

6. 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

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

8. In a multiple capacitora the plate area is
A. Increased
B. The same
C. Decreased
D. Variable
Answer : A

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

10. 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

11. What is the reading of an ohmmeter for a shorted capacitor?
A. Zero
B. Infinity
C. k
D. M
Answer : A

12. 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

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

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

15. 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

16. 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

17. 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

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

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. How many coulombs are delivered by a storage battery in 25 hours if it is supplying current at the rate of 3 A?
A. 2.592 x 105C
B. 2.592 x 103 C
C. 2.592 x 108 C
D. 2.592 x 1012 C
Answer : A

21. 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

22. The open-circuit voltage at the terminal of load RL is 60V. Under the condition of maximum power transfera the load voltage will be
A. 60 V
B. 15 V
C. 20 V
D. 30 V
Answer : D

23. 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

24. Refers specifically to steady state values of quantities in ac circuits which are complex numbers.
A. Domain
B. Scalar quantity
C. Vector quantity
D. Phasor quantity
Answer : D

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

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

27. 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

28. 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

29. In a rectangular wavea the form factor is
A.
B.
C.
D.
Answer : C

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

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

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

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

34. 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

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

36. For a carbon composition resistora typical resistance values range from
A. 2.7 to 22 M
B. 1000 to 10000
C. 10 to 10 M
D. 2.7 to 2.7G
Answer : A

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

38. 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

39. What can be used to estimate resonant frequency and to find reactance at any frequency for any value of capacitor or inductor?
A. Smith chart
B. Reactance chart
C. Impedance chart
D. Resonance chart
Answer : B

40. 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

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

42. Which component opposes voltage change?
A. Resistor
B. Inductor
C. Capacitor
D. Transistor
Answer : C

43. ³Any resistance R in a branch of a network in which a current I is flowing can be replaced by a voltage equal to IR�. This states
A. Compensation theorem
B. Reciprocity theorem
C. Millman�s theorem
D. Superposition theorem
Answer : A

44. High resistance values are a consequence of the ___ of the film.
A. Thickness
B. Length
C. Thinness
D. Area
Answer : C

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

46. In an ac wavea 30 degrees of phase is ___ of a cycle.
A. ½
B.
C.
D.
Answer : B

47. If two complex conjugates are addeda ___ components results.
A. In-phase
B. Quadrature
C. Complex
D. Outof-phase
Answer : A

48. If the inductance is decreaseda the impedance of the circuit containing a resistor a capacitor and an inductor connected in series to an ac source
A. Decreases
B. Increases
C. Decreases or increases
D. Decreasesa increases or remains the same
Answer : C

49. 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

50. 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