MCQ
The equation of a longitudinal wave is represented as $y = 20\cos \pi (50t - x)$. Its wavelength is ..... $cm$
- A$5$
- ✓$2$
- C$50$
- D$20$
✓
Answer
Correct option: B.
$2$
b
(b) By comparing it with standard equation
(b) By comparing it with standard equation
$y = a\cos (\omega t - kx)$
==>$k= \frac{{2\pi }}{\lambda } = \pi $
==> $\lambda = 2\,cm$
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