Question

A 0.35 m2 coil with 50 turns rotates at 5 radians per sec2 in a magnetic field of 0.6 Tesla. What is the value of the rms current in the coil if the coil has the resistance of 3.3 Ù?

Can you also show me how you got the answer? Thanks so much

Answer 1

Apply Faraday's law:

∫B.dS = Φ, dΦ/dt => emf

B = (Bo)sinωt is the sinusoidal magentic flux density.

Flux passing through the coil:

Φ =50(0.35)sin5t=you do it.

Emf = dΦ/dt = 17.5*5cos5t

ω = 5rad/s, f = ω/2π = 5/2π = ...
we need to convert the argument of the sinusoid to degrees
to evaluate the the emf. Use 180/Ï€

Now find max EMF from the expression. Then...
I = V/R = maxEMF/3.3= ...

Instantaneous current:

I = emf/R = (59.2/50)cos377(5) = 0.103 A

Answer 2

you just saved my life