Answer:
Amplitude changes by factor of 2 means double.
Explanation:
Given:
If the power delivered to the string is quadrupled.
From the formula of power transmitted by a sinusoidal wave on a stretched string is,
Where mass per unit length, angular speed, amplitude, wave speed, power delivered.
Here we need only two terms power and amplitude.
∝
All other quantities are constant for our problem,
Where constant
Here Power become quadruple means four times,
So amplitude changes by factor of 2 means double