Question

the rating of our car battery is 12v 80A which means that 80A current will flow when the battery is connected to a conducting wire. The internal resistance of the battery is

Answer 1

Given:

The rating of our car battery is 12v 80A which means that 80A current will flow when the battery is connected to a conducting wire.

To find:

Internal resistance of the battery.

Calculation:

We can assume that the resistance of an ideal conducting wire connected to the car battery to be zero.

Hence , we can apply Ohm's Law (assuming constant) :

$\therefore \: V = I \times R$

$= > \: 12= 80 \times R$

$= > \: R = \dfrac{12}{80}$

$= > \: R = \dfrac{3}{20}$

$= > \: R = 0.15 \: ohm$

So, internal resistance of the battery is 0.15 ohm.

Other things to know:

• When a battery is connected to a circuit it is usually observed that the output voltage is is lower than the no-load voltage, this decrease in voltage is attributed to the internal resistance of the battery.