Question

A substance through which light can pass is called a/an:
A. Light body
B. Transparent body
C. Opaque body
D. Translucent body

Answer 1

Hint: We are given a situation where a light incident on a surface of a body passes through it completely. We know that when a light is incident on a body there are three possible situations. The light can entirely pass through the body, the light can partially pass through the body and the light will get reflected back. Based on this the different bodies are classified. By finding the correct classification, we can find the solution.

Complete step by step answer:
In the question we are asked through which substance light will pass.
We know that substances or materials can be classified on the basis that whether we can pass light through them or we can pass light partially or will the light get reflected.
On the above said basis we do classify materials mainly into three classes; transparent body, opaque body and translucent body.
At first let us see what a transparent body is.
A body that allows the complete light incident on the surface of that body to pass through it is known as a transparent body. A clear empty glass, a window pane, water etc are the examples of a transparent body.
Now let us look into an opaque body.
If we pass light through a body and that body restricts any amount of light to pass through it and instead it reflects the light, then such a body is called an opaque body. Cardboards, wooden substances, bricks etc are some of the examples for an opaque body.
Now a translucent body is a body that allows only a fraction of light that is incident on its surface to pass through it. A tinted window of car, frosted glass, tissue paper etc are some of the examples for a translucent body.
From the above given definitions we can see that a substance that allows light to pass through it is a transparent body.

So, the correct answer is “Option B”.

Note:
An optical medium is a medium through which light passes. The light passing through the medium gets reflected by the inner walls and freely passes through it. Since the light gets reflected by the inner walls we can understand that the inner walls are opaque (because opaque bodies reflect the light incident on them).