Explain with the aid of a well labelled diagram a (i). Total internal reflection
(ii). Critical angle
b. State the two conditions under which total internal reflection can occur.
c. Mention two uses of total internal reflection.
d. What is the unit for measuring the refractive index?
Pls hurry

Hello...

Explanation:

a)i)Total internal reflection, in physics, complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium. The phenomenon occurs if the angle of incidence is greater than a certain limiting angle, called the critical angle.

ii)The critical angle is the angle of incidence where the angle of refraction is 90°. The light must travel from an optically more dense medium to an optically less dense medium. Figure 5.15: When the angle of incidence is equal to the critical angle, the angle of refraction is equal to 90°.

b)Two Requirements for Total Internal Reflection

The light is in the more dense medium and approaching the less dense medium. the angle of incidence is greater than the so-called critical angle.

c)The phenomenon of total internal reflection of light is used in many optical instruments like telescopes, microscopes, binoculars, spectroscopes, periscopes etc. The brilliance of a diamond is due to total internal reflection. Optical fibre works on the principle of total internal reflection.

d)There are no units for the index of refraction, because it is merely a ratio. When you use the formula n=cv , the units for c and v cancel each other out, because they are both measured in m/s, leaving no units.

HOPE IT HELPS YOU DEAR

PLEASE MARK AS BRAINLIEST