A10 mh inductor is connected in series with a 10-ohm resistor, a switch and a 6-volt battery.(a) what is the time constant of the circuit? (b) how long after the switch is closed will the current reach 99% of its final value?

Explanation:

It is given that,

Inductance of the inductor,

Resistance of the resistor, R = 10 ohms

(a) Let is the time constant of the circuit. It is given by :

(b) The current equation in RL circuit is given by :

I' = 0.99 I

t = 4.6 ms

Hence, this is the required solution.

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