A square loop of side 20 cm is moved towards the right at a constant speed of 5 cm/s . The front edge of the loop enters a 120 cm wide uniform magnetic field region at t = 0 . During which of the following time intervals is the induced emf in the loop zero?

Step-by-step solution

Time taken by the loop to completely enter the magnetic field is t₁ = side speed = 20 cm 5 cm/s = 4 s . Time taken for the front edge to reach the other end of the magnetic field region is t₂ = width of field speed = 120 cm 5 cm/s = 24 s . Between t = 4 s and t = 24 s , the loop is completely inside the uniform magnetic field. The magnetic flux through the loop remains constant during this interval. Since the rate of change of magnetic flux is zero, the induced emf is zero for 4 s Answer: 4 s < t < 24 s