Question

A wire loop with an area of 2.2×10−2 m2 is in a magnetic field of 0.37 T directed at a angle 30∘ to the plane of the loop. If the field drops to zero in 50 ms , what is the average induced emf in the loop?

Answer 1

Given:

area of loop: A = 0.022 m ²  

magnitude of magnetic field: B = 0.37 T

angle between direction of magnetic field and plane of the loop θ = 30^o  

change in time: Δt  = 50 ms = 0.05 sec

So, magnetic flux through the loop : = B A cosθ = (0.37)(0.022) cos (90-30) = 0.00407 Wb

Since: average induced emf in the loop: Here, _final = Zero.

Therefore: = - d / dt = B A cosθ / dt = 0.00407 / 0.05 = 0.0814 V