Question

The ratio of the speed of sound in nitrogen gas to that in the helium gas at 300 K is?

(a) √(2/7)

(b) √(1/7)

(c) √3/5

(d) √6/5

This question was addressed to me by my school principal while I was bunking the class.

My doubt stems from Transverse Waves topic in division Waves of Engineering Physics I

Answer 1

The correct option is (c) √3/5

Easiest explanation: v(N2)/vHe =√(γ(N2)/γHe ×MHe/M(N2))=√((7/5)/(5/3)×4/28)=√3/5.