Does light bends when it comes in contact with magnet?
Path of light is unaffected by presence of external magnetic field.
1.
Is backward wavefront possible? Why?
Wavefront is the locus of the adjacent points vibrating in the same phase. Hence, the wavefront also travels in the direction of propagation of energy by the wave. And, we know that the flow of energy does not happen from the lower potential to the higher potential. Therefore, there is no backward wavefront, flowing from lower disturbance to higher disturbance.