A coil 4.20 cm radius, containing 470 turns, is placed in a uniform magnetic field that varies with time according to B=( 1.20×10 −2 T/s )t+(2.55×10 −5 T/s4 )t4. The coil is connected to a 580-Ω resistor, and its plane is perpendicular to the magnetic field. You can ignore the resistance of the coil.
A)
Find the magnitude of the induced emf in the coil as a function of time.
B)
What is the current in the resistor at time t0 = 4.50 s ?

Respuesta :

so, b=(n/l)I
n=470
l=0.042
I=v/r

so it becomes
v(t)=BR/(470/0.042)

also, v=emf with no current so it becomes
EMF(t)=BR/(470/0.042)

you can plug the b values in to solve the emf. B=( 1.20×10 −2 T/s )t+(2.55×10 −5 T/s4 )t4