An EM wave of intensity I falls on a surface kept in vacuum

Question:

An EM wave of intensity I falls on a surface kept in vacuum and exerts radiation pressure p on it. Which of the following are true?

(a) radiation pressure is I/c if the wave is totally absorbed

(b) radiation pressure is I/c if the wave is totally reflected

(c) radiation pressure is 2I/c if the wave is totally reflected

(d) radiation pressure is in the range I/c < p < 2I/c for real surface

Solution:

(a) radiation pressure is I/c if the wave is totally absorbed

(c) radiation pressure is 2I/c if the wave is totally reflected

(d) radiation pressure is in the range I/c < p < 2I/c for real surface

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