question_answer

A convex lens is held 45cm above the bottom of an empty tank. The image of a point on the bottom of a tank is formed 36cm above the lens. Now liquid is poured into the tank to a depth of 40cm. It is found that the distance of the image of the same point on the bottom of the tank is 40cm above the lens. The refractive index of the liquid is \[\frac{8}{a}\]then value of a is.

Answer:

7.00