Question

The amplitude of sound is doubled and the frequency is reduced to one fourth. The intensity of sound at the same point will be ____________.

Options

• increased to double

• increased to four times

• decreased to half

• decreased to one fourth

Answer 1

The amplitude of sound is doubled and the frequency is reduced to one fourth. The intensity of sound at the same point will be decreased to half.

Explanation:

`"I" prop "A"^2 "n"^2`

`therefore "I"_1/"I"_2 = ("A"_1/"A"_2)^2 ("n"_1/"n"_2)^2`

` = ("A"/(2"A"))^2 ((4"n")/"n")^2`

` = 16/4 = 4`

`therefore "I"_2 = "I"_1/4`