Which of the following is used for the correction of short sightedness?

If a concave lens of focal length 12cm is used to produce a real image four times the size of the object, how far from the lens must the object be placed?

The image of an object is located 6cm behind a convex mirror. If its magnification is 0.6, calculate the focal length of the mirror

A ray of light passing through the centre of curvature of a concave mirror is reflected by the mirror at?

The most suitable type of mirror used for the construction of the search light is the?