Answer:
The power is reduced by 19 percent.
Explanation:
The formula of power is given by:
[tex]P = \frac{V^{2}}{R}[/tex]
In which V is the voltage, and R is the resistance.
I am going to use R = 1 in both cases.
With the original voltage, V = 1, we have
[tex]P = \frac{V^{2}}{R} = \frac{1}{1} = 1[/tex]
With the modified voltage, V = 0.9, we have:
[tex]P = \frac{V^{2}}{R} = \frac{0.9^{2}}{1} = 0.81[/tex]
So the power is reduced by 1-0.81 = 0.19 = 19 percent.
