___________ is the primary source of light.

______________ is an important feature of light that it always travels in a straight line when it travels in the same medium

Burning candle, oil lamp, tube light are _____________

The substances which do not allow the light to pass through them are called

_____________ occurs when earth comes in between sun and moon.

When opaque objects are placed infront of sunlight or torch light ________ is formed behind the object.

Substance which allow the light to pass through them completely are called

Human body is

Substances which allow only partial transmission of light to pass through them are called

When moon comes in between the earth and sun and cast its shadow on earth, it is called