Television signals cannot be received beyond a certain distance because :

Red light signal is used as a danger signal because –

The defect of vision in which a person cannot see the distant objects clearly but can see nearby objects clearly is called

Ramesh cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power

The minimum distance of clear vision for a normal healthy eye of human being is supposed to be :

A rainbow has a circular shape because of :