Question

A double convex lens made of a material of refractive index 1.5 and having a focal length of 10 cm is immersed in liquid of refractive index 3.0. The lens will behave as

• A. Diverging lens of focal length 10 cm
• B. Diverging lens of focal length 10 / 3 cm
• C. Converging lens of focal length 10 / 3 cm
• D. Converging lens of focal length 30 cm

Answer 1

Answer: (A)

Diverging lens of focal length 10 cm

Answer 2

By using ⇒

$f _ { l } = - 10 \mathrm {~cm}$ (i.e. diverging lens)