An electric field of 4.0 µV/m is induced at a point 2.0 cm from the axis of a long solenoid (radius = 3.0 cm, 800 turns/m). At what rate is the current in the solenoid changing at this instant?
I know the answer is 0.4 A/s, but am not sure how to get to that point.

Question

An electric field of 4.0 µV/m is induced at a point 2.0 cm from the axis of a long solenoid (radius = 3.0 cm, 800 turns/m). At what rate is the current in the solenoid changing at this instant?
I know the answer is 0.4 A/s, but am not sure how to get to that point.

anonymous · Answer

I can't seem to get the right answer:
I tried using the induction quation for a solenoid:
$$L=\frac{ \mu N ^{2}A }{ \ell }$$ and then I tried using $$V=L \frac{ di }{ dt }$$

radar · Answer

I believe some additional information may be required.  What rate is the electric field changing, what is the frequency?