B a Figure 1: A square loop in a magnetic field B 1) (i) State Faraday's law of electromagnetic induction for the induced e.m.f. in a circuit due to changing magnetic flux. (ii) Assume the axis of the loop is along the x-axis and the loop rotates in a clockwise direction with angular speed w. What is the magnetic flux penetrating the loop at any instant in time? (iii) Calculate the e.m.f. induced in the loop. (iv) Sketch the variation of the flux penetrating the loop and the e.m.f with time for a loop with a = 2 cm, B = 2 T and angular velocity 120t radians/s. Assume the plane of the loop is perpendicular to the magnetic field at time t = 0. v) If the loop is held fixed with its plane perpendicular to the direction of B, calculate B(t) which will induce the same e.m.f. in the loop as in (iv). (v) State one application of a rotating loop in a magnetic field.