Electrical Circuits MCQ Solved Paper for SSC JE

1. 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

2. 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

3. The potential gradient in a cable is maximum in
A. Conductor
B. Outer sheath
C. Insulation
D. Uniformly all over
Answer : A

4. 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

5. Which of the following is the peakiest?
A. Square wave
B. Sinusoidal wave
C. Triangular wave
D. Rectangular wave
Answer : C

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

7. The resistance of an insulator ___ when its temperature is increased.
A. Decreases
B. Remains the same
C. Increases
D. Varies
Answer : A

8. 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

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

10. 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

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

12. 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

13. And ideal current source has an internal conductance of _____ siem
A. Infinite
B. One
C. Zero
D. One million
Answer : C

14. 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

15. 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

16. 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

17. Which of the following is not considered a physical factor affecting resistance?
A. Length
B. Material type
C. Temperature
D. Cross-sectional
Answer : C

18. 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

19. 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

20. Which is considered as the effect of a dielectric material?
A. Increasing capacitance
B. Decreasing capacitance
C. Reducing the working voltage
D. Increasing the distance between the plates
Answer : A

21. 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

22. 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

23. In dividing or multiplying phasor quantitiesa ___ form is used.
A. Polar
B. Rectangular
C. Trigonometric
D. Exponential
Answer : A

24. 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

25. Two capacitors of capacitance 9 F and 18 F in series will have a total capacitance of
A. 27 F
B. 162 F
C. 6 F
D. 180 F
Answer : C

26. Which of the following does not affect resistance?
A. Resistivity
B. Cross-sectional area
C. Mass
D. Length
Answer : C

27. 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

28. 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

29. 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

30. 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

31. 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

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. 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

34. 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

35. A lead conductor has a resistance of 25 at 0 �C. Determine its resistance at -30 �C
A.
B.
C.
D.
Answer : A

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

37. What is considered as the most important value of a sine wave?
A. Effective value
B. Peak value
C. Average value
D. Instantaneous value
Answer : A

38. What rating of a resistor determines its ability to absorb heat?
A. Wattage
B. Ohmic
C. Current
D. Voltage
Answer : A

39. 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

40. 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

41. A capacitor requires 12 C of charge to raise its potential of 3 V. What is the capacitance of the capacitor?
A. 36 F
B. 15 F
C. 0.25 F
D. 4 F
Answer : D

42. A law which states that when a constant electromotive force is applied to a circuit consisting of a resistor and capacitor connected in seriesa the time taken for the potential on the plates of the capacitor to rise to any given fraction of its final value depends only on the product of capacitance and resistance.
A. Child�s law
B. CR law
C. Coulomb�s law
D. Debye T3 law
Answer : B

43. 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

44. 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

45. What is the resonant frequency of a circuit when L of 3 microhenrys and C of 40 picofarads are in series?
A. 14.5 kHz
B. 145 MHz
C. 14.5 MHz
D. 145 kHz
Answer : C

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

47. If resonant frequency is 10 kHz and quality factor is 50a then
A. Bandwidth is 200 Hz
B. XL= is 50a000
C. R is 50
D. XC= is 50a000
Answer : A

48. What is the total capacitance of 10 capacitorsa each of 20 F in series?
A. 200 F
B. 2 F
C. 100 F
D. 0.5 F
Answer : B

49. A trimmer is a variable capacitor in which capacitance is varied by changing the
A. Number of plates
B. Dielectric
C. Distance between plates
D. Plate area
Answer : C

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