`A` sings with a frequency `n` and `B` sings with a frequency `1//8` that of `A`. If the energy remains the same and the amplitude of `A` is `a`, then amplitude of `B` will be

Options

A. `a_(0)`
B. `2a_(0)`
C. `8a_(0)`
D. `16a_(0)`

Answer

C

Explanation

Power factor
`cosphi=(R)/(z)`,
where impedence `z=sqrt(R^(2)+(X_(L)-X_(C))^(2))`
where `(X_(L)-X_(C))` in known as reactance
`because cosphi=(3)/(5)=(R)/(Z)impliesZ=5`
and `Z=sqrt(R^(2)+(X_(L)-X_(C))^(2))implies(X_(L)-X_(C))=4`