Question

A is singing a note and at the same time B is singing a note with exactly one-eighth the frequency of the note of A. The energies of two sounds are equal, the amplitude of the note of B is

• A. Same that of A
• B. Twice as that of A
• C. Four times as that of A
• D. Eight times as that of A

Answer 1

The correct option is D

Eight times as that of A

Energy ∝ $a^2{n}^2\Rightarrow \frac{a_B}{a_A}=\frac{n_A}{n_B}$

$(\because$ energy is same )

$\Rightarrow \frac{a_B}{a_A}=\frac{8}{1}$