Question

During reflection _________ will not change.
(A) Wavelength
(B) Frequency
(C) Speed of light
(D) All the above

Answer 1

Reflection is the property of light to fall on some surface and then reflect back the same medium. Therefore, during reflection, the medium of light does not change.

Complete step by step answer:
Reflection is the change in direction of light when it falls on some medium. In case of reflection the light goes back to the medium it originated from.
Since the wave stays in the same medium from which it originated, the speed of the wave does not change.
Therefore, wavelength and frequency of the wave does not change in case of reflection.
Therefore, from the above explanation, the correct answer is, option (D) All the above

Additional information:
The law of reflection states that, when light falls on some surface and reflects back. Then the angle of incidence with normal is equal to the angle of reflection with normal.
i.e. ${\theta _i} = {\theta _r}$
where,
${\theta _i}$ is the angle of incidence
${\theta _r}$ is the angle of reflection
Normal is the line that is perpendicular to the surface, drawn from the point at which the light is falling on the surface.

Note: Reflection can occur at many surfaces like mirror, water surface etc.
Refractive index in case of reflection is 1 as the light does not change medium.
Practically, $100\%$ light does not reflect. There is always some part of it that will refract. We can manage the angle of incidence such that we could have the $100\%$ reflection.
The phenomena of getting $100\%$ reflection is called total internal reflection.
There is also one phenomena called refraction. In case of refraction, the light falling from one medium refracts into another medium.