# Electric Field Outside a Solenoid

1. Mar 19, 2014

### sashab

1. The problem statement, all variables and given/known data

A solenoid has a radius of 1.85 cm and 1110 turns per meter. Over a certain time interval the current varies with time according to the expression I = 2.50t, where I is in amperes and t is in seconds. Calculate the electric field 5.47 cm from the axis of the solenoid.

2. Relevant equations

E = (μ$_{0}$n/2)(di/dt)(R$^{2}$/r), r>R

Where μ$_{0}$ = 4∏x10$^{-7}$, n = 1110 turns/meter, di/dt = 2.50, R = 0.0185m, r=0.0547m
3. The attempt at a solution

After plugging in all the numbers and putting things in the right units, I got 1.09x10$^{-4}$ V/m, but this is incorrect. If someone could tell me where I went wrong, I would really appreciate it! Thanks

2. Mar 19, 2014

### sashab

Nevermind, I found my mistake!