Waves - Result Question 67
69. If the amplitude of sound is doubled and the frequency is reduced to one fourth, the intensity of sound at the same point will be
[1989]
(a) increasing by a factor of 2
(b) decreasing by a factor of 2
(c) decreasing by a factor of 4
(d) unchanged
Topic 4: Musical Sound & Doppler’s Effect
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Answer:
Correct Answer: 69. (c)
Solution:
- (c) Intensity is proportional to (amplitude) ${ }^{2}$ and also intensity $\alpha$ (frequency) ${ }^{2}$. Therefore, intensity becomes $\frac{2^{2}}{4^{2}}=\frac{1}{4}$ th
