How do i do induced emf?

Question

i thought it was E(induced emf)=-N(numberofturns)deltaphi / delta t(time)

where phi is BA...

can someone help?

A rectangular loop of wire is pulled at a constant speed of 0.65 m/s into a perpendicular constant magnetic field of 0.41 T. The dimensions of loop are 0.55 m by 0.32 m and the loop moves parallel to the long side. Calculate the induced emf around the loop.

Answer 1

You're pretty much there. Rewrite it so that emf=delta(BA)/delta(t).

Now since B is constant you can rewrite it as emf = B*(delta(A)/delta(t))

delta(A)/delta(t) is the change in area thats in the field with change in time. Since the loop is moving parallel to the long side then the change in area over time is its velocity times the the short side. Fill all that in and you have your answer.

Once the loop is entirely in the field there will be no more changing flux (phi) so there will be no more induced emf.