2024 Re-NEET WavesTravelling wave equation - frequency Medium Question 4 of 59 in Waves

The displacement of a travelling wave $y=C\sin\dfrac{2\pi}{\lambda}(at-x)$ where t is time, x is distance and $\lambda$ is the wavelength, all in S.I. units. Then the frequency of the wave is

A $\dfrac{2\pi\lambda}{a}$
B $\dfrac{2\pi a}{\lambda}$
C $\dfrac{\lambda}{a}$
D $\dfrac{a}{\lambda}$

The answer is D.

Solution

$y=C\sin\left(\dfrac{2\pi}{\lambda}at-\dfrac{2\pi}{\lambda}x\right)$. Comparing with $y=A\sin(\omega t-kx)$: $\omega=2\pi f=\dfrac{2\pi a}{\lambda}\Rightarrow f=\dfrac{a}{\lambda}$.

Concept Travelling wave equation - frequency

Waves in past papers

59 questions from this chapter have appeared across 25 exam years.