Question

$\text{ Arrange the following in increasing order of focal length of convex lens:}$
$(A)$ $F_v$, focal lengths of violet
$(B)$ $F_r$, focal lengths of red
$(C)$ $F_b$, focal lengths of blue
$(D)$ $F_y$, focal lengths of yellow
$\text{Choose the correct answer from the options given below:}$

• A. (A), (B), (C), (D)
• B. (A), (C), (D), (B)
• C. (B), (A), (D), (C)
• D. (C), (B), (D), (A)

Answer 1

Answer: (D)

(C), (B), (D), (A)

Answer 2

The refractive index is higher for violet light, which means its focal length is shorter compared to red, yellow, and blue. Therefore, the correct increasing order of focal lengths is (C), (B), (D), (A).