1. The problem statement, all variables and given/known data A metal ring of radius r = 24 cm surrounds a solenoid of radius R = 2 cm and 10000 turns. The magnetic field inside the solenoid changes from 5 T to 3 T in 0.1 s. Find the magnitude of the non-Coulomb electric field along the ring. Answer in units of V/m 2. Relevant equations emf = -N*d(flux)/dt = -N*db/dt*A emf = integral of E*dl 3. The attempt at a solution Ok, so i pretty much just plugged in numbers. for the emf: emf = -10000*(3-5)/0.1*pi*0.02^2 = 251.3 volts. For the electric field: E = emf/L = 251.3/2*pi*0.24 = 166.7 V/m Unfortunately, the computer keeps saying i'm wrong. Am I really doing something wrong? This seemed pretty straight forward.