Question

What will happen to spherical wavefronts, emanating from a point source after strike a plane reflecting surface?

• A. They will remain spherical with the same curvature, both in magnitude and sign
• B. They will become plane wave fronts
• C. They will remain spherical, with the same curvature, but sign of curvature reversed
• D. They will remain spherical, but with different curvature, both in magnitude and sign

Answer 1

Answer: (C)

Above diagram represents the reflection of a spherical wavefront from a plane surface. From the diagram we can see that after reflection the wavefront still remains spherical but the centre of curvature of wavefront shifts from left side of plane mirror to right side of plane mirror.
Hence, the wavefront will remain spherical, with the same curvature, but sign of curvature reversed