The magnetic field inside a 5.0cmdiameter solenoid is 2.0 T and decreasing at 3.80 T/s.
What is the electric field strength inside the solenoid at point 1.80 cm from the axis?
Mind you, I’m going to choose the best answer. many thanks
2 Answers

I’m guessing this problem is as simple as multiplying the magnetic field magnitude decrease by 2*Pi*d. Some units cancel out to give the units of an electric field. So if I am not mistaken, it will be like this…
E = 3.80 T/s x (2 x Pi x 0.018 m) = 0.430 N/C
Please let me know if I am incorrect.

E= (r/2)(dB/dt)
where r is 1.8 cm (or 0.018 m)
dB/dt is the change, or 3.8 T/s
Plug it into the equation and the answer should be in V/m