A 12-V automobile storage battery has an internal resistance of 0.004 ohms. A) Find the current and power dissipation when the terminals are connected by a conductor of negligible Resistance B) The battery delivers 80A to the starter motor. What resistance would draw the same current? C) How much power is supplied to the motor?

Question

A 12-V automobile storage battery has an internal resistance of 0.004 ohms. A) Find the current and power dissipation when the terminals are connected by a conductor of negligible Resistance  B)  The battery delivers 80A to the starter motor. What resistance would draw the same current? C) How much power is supplied to the motor?

Damon · Answer

i = V/R = 12 / .004 amps P = i V = 144/R Joules i = 80 R = V/i = 12/ 80 external resistance Rx = R - .004 power to motor = i^2 Rx = 6400 Rx