Figures 27.1b and 27.2 actually describe the same situation, just from the viewpoints of two different inertial reference frames. In Fig. 27.2, in the reference frame of the magnet, you can think of the induced current as arising from the magnetic force on the electrons in the coil (motional emf). From the coil’s reference frame (Fig. 27.1b), how would you describe the origin of the induced current? (This comparison played an important role in Einstein’s thinking about relativity, and the phrase “the reciprocal electrodynamics action of a magnet and a conductor” appears in the second sentence of Einstein’s 1905 paper introducing the special theory of relativity.

 

Transcribed Image Text:

A rightward-moving magnet results in a current. (b)