Magnetic flux and emf through a rotating ring

captainjack2000
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Sorry I don't quite know how that happened!
Any way the question is
"A metal ring of radius R rotates with constant angular velocity about a diameter. Perpendicular to the rotation axis is a constant magnetic field B. Calculate as functions of time
a) magnetic flux through ring
b) emf induced

I know magnetic flux = BAcoswt
so emf = -magnetic flux/dt = ABwsinwt
 
arent you missing a minus sign in your final answer?
 
emf = -dphi/dt = -d/dt(BAcoswt) = -(-BAwsinwt) = ABwsinwt
i think
I am a bit confused by the fact that they say "about a diameter" how does this change things?
 
ok. yeah my bad with the minus. the diameter bit just tells you the way its rotating its not rotating about the surface normal but rather like a dynamo would.
 
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