Question

Assertion :When a prism of $\mu =3/2$ is immersed in water $(\mu =4/3)$, deviation through the prism becomes $1/4^{th}$ of the deviation, when the prism is in air. Reason: It follows from $\delta =(\mu -1)A$

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

We know,

$\delta =({\mu }_{rel}-1)A$

where

${\mu }_{rel}=\frac{{\mu }_{glass}}{{\mu }_{surr}}$

$\text{In part 1}$

${\mu }_{rel}=\frac{3}{2}$,

$\delta =(\frac{3}{2}-1)A$

${\delta }_1=\frac{A}{2}$

$\text{In part 2}$

${\mu }_{rel}=\frac{\frac{3}{2}}{\frac{4}{3}}=\frac{9}{8}$

${\delta }_2=(\frac{9}{8}-1)A$

and it is clear that ,

${\delta }_2=\frac{{\delta }_1}{4}$

hence,

assertion is correct and reason is the correct explanation for the assertion.

Option $\text{A}$ is correct.