Question

 A long thin solenoid has radius 2.40 cm and 1000 turns per meter. The current in the solenoid is increasing at a constant rate of 50.0 A/s. Determine the magnitude of the induced electric field at a point inside the solenoid and 0.80 cm from the axis of the solenoid.

Answer 1

$B=\mu_0nI,$

$\frac{dB}{dt}=\mu_0n\frac{dI}{dt}=0.063~\frac Ts,$

$E=\frac l2\cdot\frac{dB}{dt}=2.5\cdot 10^{-4}~\frac Vm .$