On heating a liquid, the refractive index generally

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 convex lens is dipped in a liquid, whose refractive index is equal to the refractive index of the lens. Then, its focal length will

If a convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens, then lens acts like a

A convex lens of focal length 20 cm in air is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Now the focal length will be

A convex lens is immersed in a liquid, whose refractive index is equal to the refractive index of the material of the lens. Then its focal length will