Electromagnetism - SS2 Physics Past Questions and Answers - page 5

The magnitude of the induced emf can be calculated using Faraday's Law:

   emf = -N x d(BA)/dt,

  where N is the number of turns in the loop, B is the magnetic field, A is the area of the loop, and dt is the change in time.

   Given:

   N = 1 (single loop)

   B = 0.5 T

   A = π x (0.1 m)2 = 0.0314 m2

  dt = 0.2 s

   Plugging these values into the formula:

   emf = -1 x (0.5 T) x (0.0314 m2) / (0.2 s)

  emf = -0.025 V

  The magnitude of the induced emf is 0.025 V (rounded to two decimal places).

The magnitude of the induced emf can be calculated using Faraday's Law:

   emf = -N x dΦ/dt,

  where N is the number of turns in the coil, dΦ/dt is the rate of change of magnetic flux.

   Given:

   N = 200

   dΦ/dt = 50 T .m2/s

   Plugging these values into the formula:

   emf = -200 x (50 T .m2/s)

  emf = -10,000 V

  The magnitude of the induced emf is 10,000 V. Since the emf is negative, we take the absolute value, which is 10,000 V (rounded to the nearest whole number).