An emf is induced in a conducting loop of wire 1.22 m long as its shape is changed from square to circular. Find the average magnitude of the induced emfif the change in shape occurs in 4.25 s and the local 0.125 T magnetic field is perpendicular to the plane of the loop.

The induced emf in the loop is

Explanation:

Given that,

Length of the wire, L = 1.22 m

It changes its shape is changed from square to circular. Then the side of square be its circumference, 4a = L

4a = 1.22

a = 0.305 m

Area of square,

Circumference of the loop,

Area of circle,

The induced emf is given by :

So, the induced emf in the loop is

answergravity;

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.