Induced Emf?

Question

consider a square loop of wire, with each side measuring 0.50 m, the loop is located in the plane of your test paper. the wire loop is place in a B field that is perpendicular to the loop, coming out of the paper, and is changing at a rate of 0.05 T. calculate the induced Emf and the direction that the current flows.

Answer 1

I think you mean it's increasing at a rate of 0.05 T/s.

The magnitude of the EMF is given by the magnitude of

d(phi) / dt

where phi is the magnetic flux, given by

phi = BA, where A is the area of the loop.

So the magnitude of the EMF is

d(BA)/dt = A (dB/dt) = (0.50m)^2 (0.05T/s) = 0.0125 V

The EMF is 0.0125 V.

Now, as for the direction, the B field is increasing in the "out of the paper" direction, so the induced magnetic field in the wire must be opposite to this (ie. into the page).  This means the current must flow clockwise in order for the induced magnetic field to be into the page in conformity with the right hand rule.