Question

A point object is kept at a distance of $60cm$ from the combination of two identical thin prisms (prism angle = $4^0$ & refractive index = $1.5$) as shown in figure. If distance between the two images formed by the combination is $\frac{x\pi }{3}$ cm approximately, then $x$ is:

Answer 1

Image formed by this prism will be at two points.

The distance between two images is given by

$2(\mu -1)A.D$

$D=$ Distance from prism of an object

$=2(\frac{3}{2}-1)\times A.D$

$A=$ Angle of prism $=4^{\circ }$

$4^{\circ }$$=\frac{\pi }{180}\times \left(4\right)$

$=2\left(0.5\right)\times 4\times \frac{\pi }{180}\times 60=\frac{4\pi }{3}$