Question

The equation of a wave propagating in a string is $y=2\cos \pi (100t-x)$. Its wave length will be

• A. $2cm$
• B. $5cm$
• C. $2m$
• D. $50cm$

Answer 1

Answer: (C)

$2m$

A wave is represented by $y=A\cos (\omega t-kx)$

where $k=\frac{2\pi }{\lambda }$

Here $k=\pi$

Thus $\pi =\frac{2\pi }{\lambda }$

$⟹\lambda =2m$