# What is the coils inductance?

1. Nov 19, 2007

### Xaspire88

A coil has a resistance of 2.10 ohms. The potential difference across the coil is 11.6 V at an instant when the current through the coil is 5.00 A and is decreasing at a rate of 36.0 A/s. What is the coils inductance?

I thought i could use the equation

X=2pi fL to solve for L.. but i am confused as to whether or not 36.0 A/s is my frequency and if i can use 2.10 ohms as my X value. perhaps i am looking at it in the wrong way.

2. Nov 19, 2007

### Xaspire88

Induced emf is $$\epsilon=-L\frac{di}{dt}$$