Q. A wave frequency us y=0.1 sin [100$\ \pi t - kx$] and wave velocity is $100^{- 1}$, its wave number is equal to
A) $1m^{- 1}$
B) $2m^{- 1}$
C) $\pi m^{- 1}$
D) $2\pi\ m^{- 1}$
Explanation
(c) The standard equation of wave is
Y=a sin (ωt-kx)
Where a is amplitude, ω the angular velocity and x the displacement at instant t.
Given equation is
Y=0.1sin (100πt-kx)
Comparing Eq. (i) with Eq. (ii), we get
$\therefore Wave\ number = \frac{\omega}{v} = \frac{100\pi}{100} = \pi m^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.