Answer:
We can calculate the intensity of the magnetic field using this expression,
Induced EMF = nBπr²cos θ/Δt
where
n = number of turns of coil = 350
B = Magnetic field intensity =?
r = radius of the coil =4.2cm =0.042m
t = time taken for the change = 0.08s
θ = angle of the rotation in degree = 90deg
Now, note that the wire is perpendicular to the field initially, which gives the induced EMF, 12V but at angle 90deg, it gives another EMF =0V, because it is parallel here.
So, we will take an average of these two results to arrive at our answer.
12+0= (350*B*π*0.042²cos 0)/0.08 V
B = 12/24.255 = 0.495 Tesla
the intensity of the magnetic field = 0.495 Tesla
