For light diverging from a point source

Options

A. the wavefront is spherical
B. the intensity decrease in proportion to the distance squared
C. the wavefront is parabolic
D. the intensity at the wavefront does not depend on the distance.

Answer

A, B

Explanation

(a,b) Consider the diagram in which light diverges from a point source (O).
ltbtgt Due to the point source light propagates in all direction symmetrical and hence, wavefront will be spherical as shown in the diagram.
If power of the source is P, then intensity of the source will be .
`I=(P)/(4 pi r^(2))`
where, r is the wavefront at any time.