Waves - Result Question 31
31. The frequency of sinusoidal wave $y=0.40 \cos$ $[2000 t+0.80]$ would be
[1992]
(a) $1000 \pi Hz$
(b) $2000 Hz$
(c) $20 Hz$
(d) $\frac{1000}{\pi} Hz$
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Answer:
Correct Answer: 31. (d)
Solution:
- (d) Given $y=0.40 \cos [2000 t+0.80]$
Comparing with the standard equation
$y=A \cos (2 \pi v t+\phi)$
We get angular frequency, $2 \pi \nu=2000$ $v \Rightarrow \frac{2000}{2 \pi}=\frac{1000}{\pi} Hz$
