question_answer 32)

  The magnetic field of a beam emerging from a filter facing a floodlight is given by B = 12 x 10-8 sin (1.20 x 107 z ? 3.60 x 1015t) T. What is the average intensity of the beam ?

Answer:

                  Here,     B = 12 x 10-8 sin (1.20 x 107 z - 3.6 x 1015 t) Comparing it with,we have