Question

When we inhale helium gas funny sound appear which is due to:
(A) High density of helium than air
(B) High density of air than helium
(C) Low density of helium than air
(D) Reaction between air and helium

Answer 1

Hint: When we inhale the helium gas, actually the sound waves travel twice faster than the normal air. This is due to the presence of helium gas around our vocal cords.

Complete step by step solution:
We would have heard about this earlier that inhalation of helium gas gets out funny sounds when we try to speak.
-The sound of our normal voice is dependent on a number of factors. Alongside the air we breathe, the shape of our mouth, throat, the position of tongue and lips all factors contribute to the uniqueness of our sound.
-Our voice gets generated in the larynx and it contains vocal cords. Then it passes through various membranes.
-The air we breathe contains mainly nitrogen and oxygen gas because atmospheric air consists of mainly these two gases.
-Now, helium is less dense than regular air. That is the reason why we use it in the balloons.
-So, when we inhale helium, due to its low density our sound waves travel twice as much as normal air. So, it also travels more swiftly across our vocal cords. That results in funny sounds after we breathe helium gas.
Therefore, we can say that funny sounds appear due to the lower density of helium than air.

So, the correct answer is (C).

Note: Note that helium does not change the pitch of our voice. That means that the vibration of the vocal cords is the same. The sound changes only by the fact that it can travel quickly in the helium gas.