Problem:
Given:

A 100W resistor is connected in series with a 250mH inductor.

Find:

The time constant of the circuit

 

Procedure:  
1. Set  up the appropriate equation

t =

L
R
 
2. Substitute the known values

t =

250 x 10-3
100

 

 
3. Do the math
250 x 10-3 = 2.5 x 10-3
100
 
Solution

t = 2.5mS

 

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