For a transverse wave, what is a wavefront? A a line joining all points on the same crest of a wave
B a line showing the displacement of a wave
C the energy content of a wave
D the first part of a wave to reach a point

Explanation:

A wavefront is the long edge that moves, for example, the crest or the trough. Each point on the wavefront emits a semicircular wave that moves at the propagation speed v. These are drawn at a time t later, so that they have moved a distance s = vt.

 wavefront is the long edge that moves, for example, the crest or the trough

the higher the current the higher the mag field around it the higher the influence on the compass