21. 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. 5A
B. 10A
C. 0 A
D. 20A
22. 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. 5A
B. 10A
C. 15A
D. 20A
23. 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. 5.44A
B. 4.32A
C. 6.56A
D. 2.34A
24. 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. 5.4V
B. 10.8V
C. 0 V
D. 2.7V
25. Among the following, which is the right formula for decay in an inductive circuit?
A. i = I(1 − e − t/time constant)
B. i = I(1 − et /time constant)
C. i = (1 − e − t /time constant)
D. i = I(e − t /time constant)
26. The discharging time constant of a circuit consisting of an inductor is the time taken for the voltage in the inductor to become __________ % of the initial voltage.
A. 33
B. 63
C. 37
D. 36
27. 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 voltage across the inductor.
A. 5V
B. 10V
C. 0 V
D. 20V
28. 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 voltage across the inductor.
A. 5V
B. 10V
C. 0 V
D. 20V
29. An RL network is one which consists of ____________
A. Resistor and capacitor in parallel
B. Resistor and capacitor in series
C. Resistor and inductor in parallel
D. Resistor and inductor in series
30. If the switch is opened at t = 0, what is the current in the circuit?
A. 0A
B. 1A
C. 2A
D. 3A