Question

Change in the direction of propagation of light when it passes from one medium to another is called?
A. reflection
B. refraction
C. diffraction
D. scattering

Answer 1

Hint: Refraction of light is one of the commonly observed phenomena, but other waves like sound waves and water waves also experience refraction.
During refraction the frequency of the refracted ray remains constant; though speed of light changes on refraction.

Complete answer:
Reflection is defined as the change in direction of a wave at a surface boundary between two media so that the wave returns into the medium from which it originated.

When a wave travels from one medium to another, the change in its direction occurs. This phenomenon of change in direction of a wave passing from one medium to another is known as refraction.
Diffraction is a phenomenon that occurs when a wave falls on an obstacle of a size comparable to its wavelength. Due to diffraction, when waves pass around obstacles it spreads out or bend near its edges.
Scattering is defined as the phenomenon in which light rays get deviated from their straight path on striking an obstacle like dust or gas molecules, water vapours etc. The particles which scatter light are known as scatterers.
Since, Change in the direction of light when it passes from one medium to another is called refraction.

So, the correct answer is “Option B”.

Additional Information:
Interference is a phenomenon in which two waves superimpose to form a resultant wave of greater, smaller or the same amplitude. The amplitude of resultant waves depends on phase difference between the two waves.

Note:
The bending of a wave when it passes from one medium to another is known as refraction. This is caused due to differences in density between the two mediums.
The angle of refraction can be determined using Snell’s law which says, “ ratio of the sine of angle of incidence to the sine of the angle of refraction is a constant.”