The coil of an AC dynamos is of dimesnsions 5cm, 10cm. it consists of 420 turn, .

Question

it's put in a uniform magnetic flux density 0.4 T such that the plane of the coil was perpendicular to the field. if the coil rotates at rate of 1000 rotation/min Calculate the induced emf in each of the following positions: A)after 1/4 cycle from the first position. B)after rotation at an angle of 150 fromthe first position C)then calculate the mean value of the induced emf through 1/4 of rotation from the first position‏