If amplitude doubles, power increases by what factor?

If amplitude doubles, power increases by what factor?

• A. 2x
• B. 4x
• C. 8x
• D. 1x

Answer: (B)

Power in a simple wave system scales with the square of the amplitude. If the amplitude doubles to 2A, the power becomes proportional to (2A)^2 = 4A^2, which is four times the original power. So the power increases by a factor of four. Doubling the amplitude doesn’t just double the power or leave it unchanged; the square relationship makes it quadruple.

Power in a simple wave system scales with the square of the amplitude. If the amplitude doubles to 2A, the power becomes proportional to (2A)^2 = 4A^2, which is four times the original power. So the power increases by a factor of four. Doubling the amplitude doesn’t just double the power or leave it unchanged; the square relationship makes it quadruple.