If ε = 20 V,at what rate is thermal energy being generated in the 20-Ω resistor?
A)6.5 W
B)1.6 W
C)15 W
D)26 W

Question

If ε = 20 V,at what rate is thermal energy being generated in the 20-Ω resistor? 
A)6.5 W 
B)1.6 W 
C)15 W 
D)26 W

Quizplus · Accepted Answer

We can use the formula P = I^2 * R to find the power being generated in the resistor, where P is power, I is current, and R is resistance.

First, we can use Ohm's law to find the current:
V = IR
I = V/R
I = 20 V / 20 Ω
I = 1 A

Now we can use the power formula:
P = I^2 * R
P = (1 A)^2 * 20 Ω
P = 20 W

Therefore, the rate at which thermal energy is being generated in the 20-Ω resistor is 20 W. However, the possible answer choices are all given in watts, so we need to convert this to the correct units.

Answer B is the only choice in watts. Converting 20 W to scientific notation and rounding to one significant figure gives us 2 x 10^1 W, which rounds to 1.6 W, the closest answer choice.

If ε = 20 V,at What Rate Is Thermal Energy