Posted by Robert on Sunday, August 12, 2012 at 11:52pm.
A square loop (length along one side = 20 cm) rotates in a constant magnetic field which has a magnitude of 2.0 T. At an instant when the angle between the field and the normal to the plane of the loop is equal to 20 and increasing at the rate of 10/s, what is the magnitude of the induced emf in the loop?
The answer is 4.8 mV, but I keep getting 2.7
I used E = NABwsin(wt)
Because we have no coil, we can take out N so that leave sus with BAwsin(wt)
What am I doing wrong?
THank you

Physics  Electromagnetism  Elena, Monday, August 13, 2012 at 1:42am
ω= Δα/Δt =10º/s=π/18 rad/s.
A=a²=0.04 m²,
ωt=20º
E= dΦ/dt =  d(B•A•cos(ωt))/dt =
= B•A• ω•sin(ωt) =
=2•0.04• (π/18) •sin20º = 4.775•10^3 V ≈4.8 mV