Question

An LR circuit contains an ideal 60-V battery, a 51-H inductor having no resistance, a 21-Ω resistor, and a switch S, all in series. Initially, the switch is open and has been open for a very long time. At time t = 0 s, the switch is suddenly closed. When the voltage across the resistor is equal to the voltage across the inductor, what is the current in the circuit?

Answer 1

current in the circuit is 1.428 A

Step-by-step explanation:

Given data

voltage = 60 V

resistor = 21 Ω

time = 0

to find out

current in the circuit

solution

we have given that

voltage across the resistor = voltage across the inductor

that is = 60 /2 = 30 V

we know voltage across resistor = IR

so I × R = V/2

and current I = 30 /21

so current = 1.428 A

current in the circuit is 1.428 A