Question

A list of mediums is given below.

(i) wood (ii) water (iii) air (iv) vacuum

In which of these mediums can sound travel?

• A. i & ii only
• B. i, ii & iii only
• C. iii & iv only
• D. ii, iii & iv only

Answer 1

The correct option is B

i, ii & iii only

Explanation for correct option:

Option (b): i, ii & iii only

Sound:

1. Sound is a form of energy produced by vibrations.
2. When an item vibrates, the surrounding air molecules move.
3. These molecules collide with molecules nearby, forcing them to vibrate as well.

Propagation of sound:

1. Sound is a series of pressure waves that travel through compressible substances such as air or water. (Sound may also propagate through solids, although there are other ways of propagation.)
2. Waves can be reflected, refracted, or attenuated by the medium as they travel.

Medium for the propagation of sound:

1. Depending on what it is going through, sound travels at varying rates.
2. Sound waves move the slowest through gases, the fastest through liquids, and the fastest through solids among the three media (gas, liquid, and solid).
3. Among the four given mediums i.e., wood, water, air, and, vacuum, sound waves can travel through the wood (solid), water (liquid), and air (gas).
4. But it cannot travel through a vacuum as it does not have any particles present, which is required for sound to propagate.
5. Hence, this is the correct option.

Explanation for incorrect options:

Option (a) i & ii only

1. This option is incorrect.
2. Because other than wood and water, air which is an example of gas is also able to propagate the sound waves.

Option (c) iii & iv only

1. The vacuum does not have any particles present in it, so it cannot allow sound waves to travel through it.
2. Thus, this option is not true.

Option (d) ii, iii & iv only

1. Sound waves cannot travel through a vacuum but they can travel through water and air.
2. So, this option is also incorrect.

Hence, Sound can travel through the air, water, and wood but not vacuum so, option (b) is correct.