Test: Light, Shadows & Reflections

• Transparent objects allow light to pass through them.
• Examples of transparent objects are: Air, glass, pure water, some plastics etc.
• When light encounters transparent materials, almost all of it passes directly through them. So, reading glasses are transparent.

Light is the most important thing if we have to see an object. Because until a light ray isn't incident on an object, we can't really see it. 

Light is a form of energy.
Eg. Sunlight

A shadow is formed only when a source of light is obstructed by an opaque object.

Shoe box will not form a circular shadow as it is rectangular in shape.

A black wallet absorbs most of the light. A “flat black” material having no glossy reflections absorbs the most solar energy. Conversely, light colors reflect more light than dark ones, and white reflects the most.

In the morning, when the sun rises in the east, your shadow will be seen on the west, i.e. on the opposite side.

Objects that emit light on their own are called luminous objects. Best examples of luminous objects are the sun, stars, light bulb etc. Objects that do not reflect light are known as non luminous objects.
Hence (a) option is correct

The moon is a non-luminous object and cannot emit light of its own. It only reflects the light energy falling on it from the sun.

Planets do not have nuclear fusion, they do not produce their own light. Instead, they shine with light reflected from a star.

A non-luminous body is an object that does not shines by its own light. It needs a luminous body in its surrounding whose light it can reflect and become visible.