Electrical Circuits MCQ Solved Paper for DRDO

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

2. 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

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

4. An impedance given by 90 -45� is a/an ___ impedance.
A. Inductive
B. Conductive
C. Resistive
D. Capacitive
Answer : D

5. 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

6. The ratio between the active power and the apparent power of a load in an ac circuit is called
A. Quality factor
B. Power factor
C. Power ratio
D. Power reactive
Answer : B

7. 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

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

9. The charging of a capacitor through a resistance obeys
A. Exponential law
B. Logarithmic law
C. Linear law
D. Square law
Answer : A

10. 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

11. 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

12. 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

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

14. For parallel 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 : A

15. A tank circuit is a
A. Parallel LC circuit
B. Series LCcircuit
C. A resonant circuit
D. A non-resonant circuit
Answer : A

16. What is the total resistance of a two equal valued resistors in series?
A. The difference of both
B. The product of both
C. Twice as one
D. The sum of their reciprocals
Answer : C

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

18. For greater accuracya the value of phase angle should be determined from
A. Cos
B. Tan
C. Sin
D. Sec
Answer : B

19. Which of the statements below is not true?
A. Current source is an active element
B. Resistor is a linear element
C. Voltage source is a passive element
D. Diode is a non-linear element
Answer : C

20. 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

21. At what frequency will the current in a series RLCcircuit reach its maximum value for an applied voltage of 15 V with R = 500 a L = 100 H and C= 0.001 F?
A. 503 kHz
B. 403 kHz
C. 603 kHz
D. 303 kHz
Answer : A

22. A real current source has
A. Infinite internal resistance
B. Zero internal resistance
C. Large internal resistance
D. Small internal resistance
Answer : C

23. 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

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. 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

26. A factor that states how much the resistance changes for a change in temperature?
A. Resistivity
B. Specific resistance
C. Coefficient of temperature change
D. Temperature coefficient of resistance
Answer : D

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

28. 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

29. What is the purpose of a load in an electric circuit?
A. To increase the circuit current
B. To decrease the circuit current
C. To utilize electrical energy
D. To make the circuit complete
Answer : C

30. 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

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

32. 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

33. 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

34. 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

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

36. 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

37. 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

38. Which of the following dielectric materials makes the lowest-capacitance capacitor?
A. Paper
B. Mica
C. Air
D. Electrolyte
Answer : C

39. 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

40. In a series circuit with unequal resistances the
A. Highest R has the highest V
B. Lowest R has the highest V
C. Lowest R has the highest I
D. Highest R has the highest I
Answer : A

41. 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

42. What is a closed path made of several branches of the network called?
A. Junction
B. Node
C. Terminal
D. Loop
Answer : D

43. A rheostat is a form of
A. Variable resistor
B. Variable capacitor
C. Potentiometer
D. Thermocouple
Answer : A

44. The capacitance of a capacitor is ___ relative permittivity.
A. Directly proportional to
B. Inversely proportional to
C. Equal to
D. Inversely proportional to the square of
Answer : A

45. 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

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

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

48. What theorem is generally used in the analysis of vacuum tubes?
A. Superposition theorem
B. Millman�s theorem
C. Thevenin�s theorem
D. Norton�s theorem
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. Parallel resonant circuit is sometimes called as
A. Acceptor circuit
B. Rejector circuit
C. Inductive circuit
D. Capacitive circuit
Answer : B