Light appears to travel in a straight line because –

Red light signal is used as a danger signal because –

The streaming of light beams coming from the Sun through trees is said to have suggested that light travels in straight line. The particles on the path of light beams are visible to us because

A lemon kept in water in a glass tumbler appears to be larger than its actual size. It is because of

The sky appears blue due to –

A ray of light travelling from a rarer medium to a denser medium