Question

why does the level of water in the tank sometimes appear to be rise up explain With the help of a diagram

Answer 1

It happens due to the, phenomenon of refraction of light. When the rays of light from the bottom of tank, in the denser medium, fall on the interface separating the two media, the rays of light move away from the normal after refraction. The point from which the refracted rays appear to come gives the apparent position of the tank bottom. As the rays appear to come from a point above the tank bottom, therefore, the tank seems io be raised.