Question

Light : Ray :: Sound?
A. Wave
B. Hear
C. Audio
D. Pitch

Answer 1

Hint: There are two types of waves, transverse and longitudinal. A transverse wave is the one which travels through a medium, making crests and troughs. Wave on a string is an example of a transverse wave. A longitudinal wave is the one which travels through the medium making compressions and rarefactions. Sound waves are examples of longitudinal waves.

Complete answer:
Light: Light is that part of the electromagnetic spectrum, which is visible to us. As it is part of the electromagnetic spectrum, light is an example of an electromagnetic wave. We are able to see only that object, from which light falls on our eye, either directly by generation from the body or by reflection from the body. It is an example of transverse waves and hence it doesn't need any medium to travel.
Sound: Sound is a form of wave which travels through a medium by disturbing the particles of the medium. This type of wave travels in the form of compression and rarefactions hence is called the longitudinal wave and requires a medium to propagate.
Now, as per the question, the best option for light ray and sound must be that these belong to waves.

So, the correct answer is “Option A”.

Note:
Any wave will obey some type of trend in variation of its parameters like velocity and displacement, which is called the equation of wave. The wave equation is generally of the form $A\ sin \left ( \omega t - kx \right )$ where symbols have their usual meaning. Hence we can see that this is a beautiful equation which depends on or connects position and time in a single equation.