If a light ray is reflected from a mirror as shown in the figure, then

Options

A. the glancing angle of light ray is `45^(@)`.
B. the reflected light ray is perpendicular to the incident light ray.
C. the incident ray is deviated through an angle of `90^(@)`.
D. All the above.

Answer

D

Explanation

(i)
From the figure
`i+r=90^(@)`
But `i=r`
`2i=90^(@)`
`i=45^(@)`
`anglex+anglei=90^(@)`
`anglex=90^(@)-45^(@)`
`=45^(@)`
(ii) From the given figure `anglePOQ=90^(@)` i.e., reflected light is prependicular to incident light.
(iii) From figure, `y=90^(@)-45^(@)-45^(@)andanglePOM=angleNOQ`
`:.angleQOQ^(1)` =gngle of deviation
`=angleQON+angleNOQ^(1)`
`=45^(@)+45^(@)=90^(@)`