(i) What is meant by the term ‘critical angle’ ? (ii) How is it r

1.	(i) What is meant by the term ‘critical angle’ ? (ii) How is it related to the refractive index of the medium ? (iii) Does the depth of a tank of water appear to change or remain the same when viewed normally from above ?
Answer» (i) Critical angle is the angle of incidence in the denser medium corresponding to which the angle of refraction in the rarer medium is 90°. (ii) aμg = cosec ic where ic in the critical angle. (iii) Depth remain the same. Apparent depth = Actual depth.

(i) What is meant by the term ‘critical angle’ ? (ii) How is it related to the refractive index of the medium ? (iii) Does the depth of a tank of water appear to change or remain the same when viewed normally from above ?

Answer»

(i) Critical angle is the angle of incidence in the denser medium corresponding to which the angle of refraction in the rarer medium is 90°.

(ii) aμg = cosec ic where ic in the critical angle.

(iii) Depth remain the same. Apparent depth = Actual depth.