Q.4. A 0.25 m long coil cosists of 560 square turns 6.5 cm on a side. the coil is placed in a uniform magnetic field of strength 1.2 T. Inititally the coil is oriented so that its axis coincides with the magnetic field direction. The coil is then rotated $90°$ about an axis perpendicular to the magnetic field diresction in 0.20 ms. What is the magnitude of the emf induced in the coil?