A straight conductor of length 0.5 m moves at 4 m per second perpendicular to a field of 0.2 T. The emf induced across its ends is

  • A. 0.4 V
  • B. 0.1 V
  • C. 4 V
  • D. 2.5 V

Explanation

The motional emf is BvL, that is 0.2 multiplied by 4 multiplied by 0.5, giving 0.4 V. The formula assumes the conductor, the field and the motion are mutually perpendicular; otherwise only the perpendicular components count. This is the elementary form of Faraday's law, since the conductor sweeps out area at a rate vL.

Related questions