Electric Circuits Short Questions(MCQs) & Answers

41 Which of the following is normally designed for high value of quality factor?

A Resistance

B Inductance

C Capacitance

D None of the above

View Answer

Answer: Inductance

42 The resultant magnetic flux generated in the closed surface will be

A Zero

B Continuous

C Constant

D Unity

View Answer

Answer: Zero

43 Which of the following phenomenon takes place when an electromagnetic wave propagates through free space?

A Reflection

B Phase shift

C Attenuation

D Distortion

View Answer

Answer: Attenuation

44 Find the change in potential energy of a system where change Q0 is carried to the charge Q1 at a distance of 10 meters with a 10 N force?

A 10 N/meter

B 100 N-meter

C 10 joules

D 50 N/meter

View Answer

Answer: 100 N-meter

45 If RC is the time constant of the R-C circuit, now much time the capacitor will take to get fully charged?

A RC seconds

B 4 RC seconds

C 3 RC seconds

D 5 RC seconds

View Answer

Answer: 3 RC seconds

46 Which of the following indicates the units of displacement density?

A Ampere-meter

B Coulomb-meter

C Coulomb/m2

D Volt m2

View Answer

Answer: Coulomb/m2

47 Which of the following statement is true?

A The current in a discharging capacitor grows exponentially

B The current in a discharging capacitor decays exponentially

C The current in the discharging capacitor grows linearly

D The current in the discharging capacitor decreases constantly

View Answer

Answer: The current in a discharging capacitor grows exponentially

48 The maximum current in the circuit of Q. 225 will be

A 1 A

B 100 A

C 2 A

D 5 A

View Answer

Answer: 1 A

49 An RC circuit is shown below, the current will reach its maximum value

A After 1000 μ sec of turning on the switch

B After 500 μ sec of turning on the switch

C After 50 μ sec of turning on the switch

D Immediately after turning on the switch

View Answer

Answer: Varying magnetic field

50 Which of the following condition is true for maximum transfer of power if the internal impedance of voltage source is Zs = R + jx

A ZL = Zs

B ZL = R – jx

C ZL = R + jx

D ZL = Zs/2

View Answer

Answer: ZL = R – jx

51 If a neon bulb of 60 watts is connected 220 V, Ac source and draws 272 mA current, what be the resistance of the bulb filament?

A 1000 Ω

B 808 Ω

C 800 Ω

D 60 Ω

View Answer

Answer: 800 Ω

52 If a night bulb is used at less brightness than rated one, which of the following method one will choose to achieve required brightness?

A Current-limiting resistor

B Potential divider

C Source Voltage Reduction

D Either (a) or (b)

View Answer

Answer: Either (a) or (b)

53 A sine wave of 220 V, 50 Hz AC will achieve its negative maximum value in

A 10 m sec

B 15 m sec

C 20 m sec

D 50 m sec

View Answer

Answer: 15 m sec

54 What will be the energy used by the battery if the battery has to drive 625 × 1016 electrons with potential difference of 10 V across the terminals?

A 5 joules

B 10 joules

C 6.25 joules

D 1.6 joules

View Answer

Answer: 10 joules

55 In the Q. 214, the circuit (b) behaves as

A Current limiting source

B Potential divider

C Light limiting source

D None of the above

View Answer

Answer: Potential divider

56 There are two circuits shown below. Which of the following statement is true?

A The lamp will be brightest when contact K moves to A in circuit (a)

B The lamp will be brightest when the contact K moves to B in circuit (a)

C The lamp will be brightest when contact K is moved to A the circuit (b)

D Circuit (a) is a potential divider

View Answer

Answer: The lamp will be brightest when the contact K moves to B in circuit (a)

57 If one cycle of a.c. waveform occurs every second, what will be the frequency of this waveform?

A 0.2 Hz

B 0.5 Hz

C 1 Hz

D 2 Hz

View Answer

Answer: 1 Hz

58 A circuit is shown below. What will be the steady state value of the current?

A 1 amp

B 2 amps

C 4 amps

D 5 amps

View Answer

Answer: 4 amps

59 The electrical circuit A and B are shown below. Which of the battery of the flowing circuit will be loaded more and by what amount of current provided resistance of bulbs are same?

A A, IA = 4IB

B B, IA = IB

C A, IB = 4IA

D B, IA = 2IB

View Answer