Question

Maximum lateral displacement of a ray of light incident $(i=90)$ on a slab of thickness $t$ is:

• A. $\frac{t}{2}$
• B. $\frac{t}{3}$
• C. $\frac{t}{4}$
• D. $t$

Answer 1

The correct option is D $t$

We know that,

For $i={90}^0$

Lateral shift is maximum

Lateral shift for a slab of t thickness

$L.S=t\times \frac{\sin (i-r)}{\cos r}$

$L.S=t\times \frac{\sin (90-r)}{\cos r}$

$L.S=t\times \frac{\cos r}{\cos r}$

$L.S=t$

Hence, the lateral shift is equal to thickness $t$