An N-turn circular wire coil of radius r lies in the xy-plane, as shown in the f
ID: 2184099 • Letter: A
Question
An N-turn circular wire coil of radius r lies in the xy-plane, as shown in the figure below. A uniform magnetic field is turned on, increasing steadily from 0 to B0 in the negative z-direction in t seconds. (Use any variable or symbol stated above along with the following as necessary: R and pi.) Find a symbolic expression for the emf, epsilon, induced in the coil in terms of the variables given. Looking down at the xy-plane from the positive z-axis, is the direction of the induced current clockwise or counterclockwise? If each loop has resistance R, find an expression for the magnitude of the induced current, I.Explanation / Answer
flux = B*A
emf = d(flux)/dt = dB/dt*area
= -B0/t *pie*r^2
Direction is clockwise
If resistance is R
then current I = V/R
I = (B0/t*pie*r^2 )/R