Question
Physics Question on Waves
If the amplitude of sound is doubled and the frequency reduced to one fourth, the intensity of sound at the same point will be
A
increasing by a factor of 2
B
decreasing by a factor of 2
C
decreasing by a factor of 1/4
D
unchanged
Answer
decreasing by a factor of 1/4
Explanation
Solution
Intensity ?(amplitude)2 and also intensity
?(frequency)2. Therefore
original I?A2ω2
I′?4A216ω2i.e.,41I