The refractive index of air with respect to glass is expressed as ""_(g)mu_(a)=(sini)/(sinr). (a) Write down a similar expression for ""_(a)mu_(g) in terms of the angles i and r. (b) if angle r=90^@, what is the corresponding angle i called ? (c) What is the physical significance of the angle i in part (b) ?

The refractive index of air with respect to glass is expressed as ""_(

1.	The refractive index of air with respect to glass is expressed as ""_(g)mu_(a)=(sini)/(sinr). (a) Write down a similar expression for ""_(a)mu_(g) in terms of the angles i and r. (b) if angle r=90^@, what is the corresponding angle i called ? (c) What is the physical significance of the angle i in part (b) ?
Answer» Answer :(a) `""_(a)mu_(g)=(SINR)/(SINI)`, (b) critical ANGLE, (c) If angle of incidence exceeds the value of `i` OBTAINED in part (b), total internal reflection occurs.