Question

The refractive index of glass is 1.520 for red light and 1.525 for blue light. Let $\quad D_{1}$ and $\quad D_{2}$ be angles of minimum deviation for red and blue light respectively in a prism of this glass, then,:

• A. $ \quad D_{1}
• B. $\quad D_{1}=D_{2}$
• C. $\quad D_{1}$ can be less than or greater than $\quad D_{2}$ depending upon the angle of prism
• D. $\quad D_{1} >D_{2}$

Answer 1

Answer: (A)

$ \quad D_{1}

Answer 2

$\quad D=\left(\mu-1\right)A$ For blue light $\quad\mu$ is greater than that for red light, $so\, D_{2} >D_{1}\cdot$