A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will
A. become zero
B. become infinite
C. become small, but non-zero
D. remain unchanged
Answer:B
A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will
A. become zero B. become infinite C. become small, but non-zero D. remain unchanged