41. Calculate the time constant of an inductive circuit having resistance 5 ohm and inductance 10H.
A. 2s
B. 4s
C. 5s
D.10s
42. Calculate the resistance in an inductive circuit whose time constant is 2s and the inductance is 10H.
A. 7 ohm
B. 10 ohm
C. 2 ohm
D. 5 ohm
43. Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm.
A. 10H
B. 20H
C. 5H
D. 15H
44. The charging time constant of a circuit consisting of an inductor is the time taken for the current in the inductor to become __________% of the initial current.
A. 33
B. 63
C. 37
D. 36
45. What is the total applied voltage in an inductive circuit?
A. V = Ri+Ldi/dt
B. V = Ri+di/dt
C. V = i+Ldi/dt
D. V = R+Ldi/dt
46. What is Helmholtz equation?
A. i = I(eRt/L)
B. i = I(1 − e − Rt/L)
C. i = I(1+e − Rt/L)
D. i = I(e − Rt/L)
47. A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the initial value of the current in the circuit.
A. 5 A
B. 10 A
C. 0 A
D. 20 A
48. A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of the current in the circuit.
A. 5 A
B. 10 A
C. 15 A
D. 20 A
49. A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of current 1s after the switch is closed.
A. 5.44 A
B. 4.32 A
C. 6.56 A
D. 2.34 A
50. A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of voltage 1s after the switch is closed.
A. 5.4 V
B. 10.8 V
C. 0 V
D. 2.7 V