Question

The current in a coil with a self-inductance of 1 mH is 2.8 A at t = 0, when the coil is shorted through a resistor. The total resistance of the coil plus the resistor is 11.0 capital omega. (a) Find the current in the circuit after 0.5 ms.

Answer 1

Given:

L = 1 mH =
`1* 10^(-3)` H

total Resistance, R = 11
`\Omega`

current at t = 0 s,

`I_(o)` = 2.8 A

Formula used:

`I = I_(o)* e^-{(R)/(L)t}`

Solution:

Using the given formula:

current after t = 0.5 ms =
`0.5* 10^(-3) s`

for the inductive circuit:

`I = 2.8* e^-{(11)/(1* 10^(-3))* 0.5* 10^(-3)}`

`I =   2.8* e^-5.5`

I =0.011 A