rotational coil induction

bpaterni

1. The problem statement, all variables and given/known data

1.A circular coil, with radius of 10 cm, and 25 turns, rotates in a constant magnetic field of
strength 2.4 T, with the axis of rotation perpendicular to the direction of the magnetic
field.

A. If the coil rotates at a frequency of 50 Hz, what is the induced peak voltage?
B. Sketch the time-dependence of the induced voltage.
C. If the magnetic field that the coil is in points down the page, which direction does the coil rotate? Answer for both cases: (1) q traveling from left to right and (2) q traveling from right to left in the coil.



2. Relevant equations

V = -N * [ dΦ / dT ]
Φ = B * A * cosθ

V = -N * B * A * ω*sinθ
ω = 2π*f

3. The attempt at a solution

A. A = π*.1^2
.031416 m^2

ω = 2π*50
314.159 rad/s

peak voltage would occur when the coil is perpendicular to the magnetic field correct? So would I put π/2 in for sin(x) and get the following?
V = 25 * 2.4 * .031416 * 314.159*sin(π/2)
1.88496 * 314.159
592.177 V
B. If A is correct, then would the time-dependence of induced emf look like a sin wave?
C. I take it I'm supposed to use the right-hand-rule and Lenz's Law for this question, but I'm slightly confused as to how to go about doing so

bpaterni

bump, I believe A and B are correct from what I understand, but I'm still having trouble with C.

comicnabster

I need help with this question too.

ted182

Yeah, I don't understand how to use the 50Hz to determine the peak voltage. I really hate this class! None of this was taught in the lesson or explained at any point. An explanation of the equations would be helpful. Please, anyone?