Electrical Circuits 1000+ MCQ with answer for UPSC IES

1. Which of the following is a preferred resistor value?
A.
B.
C. 43a000
D. 54a321
Answer : B

2. When resistance are connected in parallela the total resistance is
A. Less than the smallest resistance in the connection
B. Greater than the smallest resistance in the connection
C. Between the smallest and greatest resistance in the connection
D. Increasing and decreasing depending upon the supply voltage
Answer : A

3. How many degrees of phase represents one full cycle?
A.
B.
C.
D.
Answer : A

4. 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

5. 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

6. 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

7. A trigger circuit consisting of a capacitor of 0.01 F is connected in series with a resistor. If the circuit requires 100 Vdcto operatea determine the value of the resistor when time constant is 0.009s.
A.
B. 900 k
C. 900 M
D. 900 G
Answer : B

8. The reason why electrical appliances are not connected in series.
A. Greater electrical power saving
B. Power loss is minimum
C. Appliances have different current ratings
D. All of the above
Answer : C

9. The presence of an electric current is made known by
A. Electric shock
B. Effects produced
C. Magnetic shock
D. Flashing
Answer : B

10. Inductive reactance applies only to sine waves because it
A. Increases with lower frequencies
B. Increases with lower inductance
C. Depends on the factor 2
D. Decreases with higher frequencies
Answer : C

11. 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

12. What determines the direction of induced emf in a conductor or coil?
A. Cork screw rule
B. Fleming�s left hand rule
C. Ampere�s circuital law
D. Fleming�s right hand rule
Answer : D

13. A linear circuit is one whose parameters
A. Change with change in voltage
B. Change with change in current
C. Do not change with voltage and current
D. Change with change in voltage and current
Answer : C

14. 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

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

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

18. Form its definitiona the unit of electric fielda is the N/C and equivalent unit of is the
A. V(m)2
B. V(m)
C. V/m2
D. V/m
Answer : D

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

20. 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

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

22. Which of the following is a way of decreasing mutual inductance?
A. Moving the coils closer
B. Moving the coils apart
C. Decreasing the number of turns of either coil
D. Increasing the number of turns of either coil
Answer : B

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

24. 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

25. 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

26. The temperature coefficient of resistance of electrolytes is
A. Negative
B. Positive
C. Zero
D. Infinite
Answer : A

27. 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

28. 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

29. Which of the following has negative temperature coefficient?
A. Carbon
B. Nickel
C. Brass
D. Constantan
Answer : A

30. Which of the following materials has the lowest dielectric strength?
A. Glass
B. Paper
C. Mica
D. Teflon
Answer : B

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

32. Which of the following does not generally affect the value of a capacitor?
A. The dielectric material used
B. The surface area of the plates
C. The thickness of the dielectric
D. The voltage applied to the plate
Answer : D

33. In the 5-band method of capacitor color codinga the first band indicates
A. Temperature coefficient
B. Tolerance
C. 1stdigit
D. Capacitance value
Answer : A

34. What does a capacitor store?
A. Voltage
B. Charge
C. Current
D. Power
Answer : B

35. A switch designed to have low capacitance between its terminal when open.
A. LOCAP switch
B. AntiLOCAP switch
C. Anticapacitance switch
D. Capacitance switch
Answer : C

36. In a circuita a passive element is one which
A. Supplies energy
B. Receives energy
C. Both supplies and receives energy
D. Attenuates signal
Answer : B

37. What is the peak factor for alternating current or voltage varying sinusiodally?
A.
B.
C.
D.
Answer : A

38. The reason why electrical appliances are connected in parallel.
A. It is a simple circuit
B. This makes the operation of appliances independent with each other
C. This results in reduced power consumption
D. All of the above
Answer : B

39. Which of the following is a disadvantage of a wire-wound resistor?
A. It has reactance in radio-frequency circuits
B. It cannot handle much power
C. It draws a large amount of current
D. It cannot handle high voltage
Answer : A

40. If the output resistance of a voltage source is 4 a it internal resistance should be
A.
B.
C.
D. Infinite
Answer : A

41. As applied to a series RLCcircuita bandwidth means
A. The frequency range for maximum power transfer
B. The difference between the highest and lowest frequencies of the oscillator
C. The separation of the half-power points
D. The frequency at which XL= XC
Answer : C

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

43. 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

44. For multi-plate capacitora capacitance is proportional to
A. Number of plates less one(n ± 1)
B. Number of plates plus one(n + 1)
C. Number of plates less two(n - 2)
D. Number of plates (n)
Answer : A

45. Rationalizing the denominator of a complex number means
A. Eliminating the j component in the denominator
B. Adding j component in the denominator
C. Eliminating the j component in the numerator
D. Adding j component in the numerator
Answer : A

46. The ratio of W/VA in an ac circuit means
A. Power factor
B. Reactive factor
C. Quality factor
D. Load factor
Answer : A

47. When the movable plates of a gang capacitor completely overlap the fixed platesa the capacitance of the capacitor is
A. Halfway between maximum and minimum
B. Maximum
C. Minimum
D. Zero
Answer : B

48. 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

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

50. If three 9 mH inductors are connected in parallel without mutual inductance then the total i nductance is
A. 3 mH
B. 9 mH
C. 27mH
D. 18 mH
Answer : A