Question

A horizontal, parallel-sided plate of glass having a refractive index of 1.57 is in contact with the surface of water in a tank. A ray coming from above in air makes an angle of incidence of 34.5?with the normal to the top surface of the glass

(a) What angle does the ray refracted into the water make with the normal to the surface?

Use 1.33 for the index of refraction of water.

(b) What is the dependence of this angle on the refractive index of the glass?

Answer 1

Answer:

Part a)

$\theta = 25.2$

Part b)

there is no effect of refractive index of glass

Explanation:

As we know by Snell's law

$n_1 sin\theta_1 = n_2 sin\theta_2$

here we know that

$n_1$ = refractive index of air

$n_2$ = refractive index of glass

now we know that light strike on glass surface at an angle of 34.5 degree

so we have

$1 sin34.5 = n_2 sin\theta_2$

now this light will strike on the other surface at same angle and refract into water

so we have again

$n_2 sin\theta_2 = n_3 sin\theta_3$

here we know that

$n_2$ = refractive index of glass

$n_3$ = refractive index of water

$n_2sin\theta_2 = 1.33 sin\theta_3$

now we have

$1 sin34.5 = 1.33 sin\theta_3$

$\theta_3 = 25.2 degree$

b) there is no effect of refractive index of intermediate parallel mediums

So there is no effect of refractive index of glass