Question

A rectangular loop of copper wire of resistance r has width a and length


b. the loop is stationary in a uniform magnetic field. the magnetic field b at time t = 0 seconds is directed into the page as shown below. the uniform magnetic field varies with time t according to the relationship b = b0 cos ω t, where ω and b0 are positive constants and b is positive when the field is directed into the page. the direction of the induced current in the loop when ω t = π 2 , after the magnetic field begins to oscillate is

Answer 1

Answer:

Explanation:

b = b₀ cos ω t

When t = 0 , magnetic field will be b₀ and positive or directed into the page . This is the maximum value of magnetic field. As times goes ahead , magnetic field decreases so magnetic flux decreases . The induced emf or current will be such that it will  opposes this reduction of magnetic field. Hence , current in clockwise direction will be  generated in the coil which will generate magnetic flux into the paper.

In this way  current will be induced  clockwise.