# Inductance: Current in terms of Voltage

1. Feb 7, 2009

### a3sportback54

I'm having a bit of trouble getting the right answer for a problem in my electrical engineering textbook. The question is:

At t=0, the current flowing in a 0.6H inductance is 8A. What constant voltage must be applied to reduce the current to 0A at t=0.4s.

I'm using the equation:

$$i(t)=\frac{1}{L}\int\ v(t).dt+i(t_{0})$$ with limits 0.4s and 0s

The answer i'm getting is 12V, and the book says 10V.. which is right??

I'm using L=0.6H, i(t0)=8A, and i(t)=0A