Two thin lenses are of same focal length (f), but one is convex and the other is concave, When they are placed in contact with each other, the equivalent focal length of the combination will be :

Which of the following pair is INCORRECT for some transparent media with respect toair? (may consider the most approximate value)

Find the value of 'X' and 'h' in the following diagram.

A coin of diameter 10 cm is placed at a distance 3.5 f from the pole of a concave mirror of focal length f. The linear magnification and the diameter of the image are:

Which of the following pair is INCORRECT for some transparent media with respect toair? (may consider the most approximate value)