The red colour of the Sun at sunset and sunrise is due to –

The colour of an opaque object is due to the colour it–

The twinkling of a star is due to :

The Sun appears reddish during sunrise and sunset. The phenomenon in optics which is responsible for this appearance of the Sun is

An astronaut sees the colour of the sky as –

When beams of red, blue and green lights fall on the same spot, the colour of the light becomes :