Question
A square loop of wire of side 5 cm is lying on a horizontal table. An electromagnet above and to one side of the loop is turned on, causing a uniform magnetic field that is downwards at an angle of 30° to the vertical, as shown in the fig. The magnetic induction is 0.50 T. Calculate the average induced emf in the loop, if the field increase from zero to its final value is 0.2 s.

Solution
Given, a wire loop which is square in shape.
Side of the square loop = 5 cm
angle between B and A = 30o
Magnetic induction = 0.50 T
Area of the loop,
Magnetic flux,
where B cos θ is the component of magnetic induction perpendicular to the plane of the loop.
Therefore,
Average induced emf is
Thus, the induced emf is in an anticlockwise direction around the loop during the time when the downward magnetic flux is increasing.