When a 24.0-W resistor is connected across a 12.0-V battery,a current of 482 mA flows.What is the internal resistance of the battery?
A)0.02 W
B)0.9 W
C)25.0 W
D)49.8 W

Question

Quizplus · Accepted Answer

Using Ohm's law, we can find the total resistance: 
R_total = V / I = 12.0 V / 0.482 A = 24.9 ohms

Then, using the formula for total resistance of a circuit: 
R_total = R_internal + R_external 
we can solve for the internal resistance: 
R_internal = R_total - R_external = 24.9 ohms - 24.0 ohms = 0.9 ohms

So, the answer is B) 0.9 ohms.

When a 240-W Resistor Is Connected Across a 12