The graph correctly representing the variation of image distance 'v' for a convex lens of focal length ‘f’ versus object distance ‘u’ is ___________.
Fill in the blank with the correct answer from the options given below.

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:

The appearance of a stick at the interface when immersed in water is an example of___________.