Liquid lens experiment to find refractive index using mercury
Answers
To find the focal length of the convex lens:
The plane mirror is placed horizontally on the base of the retort stand with its reflecting surface upwards.
The given convex lens is placed over the plane mirror.
The pointer is arranged horizontally on the clamp of the retort stand, vertically above the lens.
Looking from above, the height of the pointer is adjusted such that the inverted image of the pointer is obtained.
The height is further adjusted so that the image coincides with tip of the pointer without parallax. The image and object will be of the same size.
The distance of the pointer from the top (y1) and bottom (y2) of the lens are measured. The average of these values gives the focal length of the f1 of the convex lens.