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Faraday's right-hand rule

Faraday proposed a simple rule for giving the direction of the induced current as follows:

If the thumb and first two fingers of the right hand are held at right angles and the first finger is pointed in the direction of the magnetic field and the thumb in the direction of motion then the second finger gives the direction of the induced current (Figure 1).

Faraday's and Lenz's laws may be tested by the following simple experiments:

(a) rotating a metal disc at a constant rate in a magnetic field and measuring the e.m.f. generated between the rim and the axle;

(b) moving a bar magnet within a solenoid connected to a meter;

(c) rotating a magnet near a coil connected to a cathode ray oscilloscope.

(See also Induced emf)
© Keith Gibbs 2011