00:01
We're given a circuit diagram which i've reproduced here with a battery of 24 volts, and the terminal voltage of the battery is 21 .2 volts.
00:18
And we have a current of 4 ampairs flowing through the circuit.
00:23
And there is an internal resistance associated with your battery, lower case r, and a resistor, uppercase r in the circuit.
00:33
And in part a, you're asked to find the internal resistance lowercase r of the battery.
00:41
And to do this, you use the equation 25 .15, which tells us that the terminal voltage is equal to the emf or battery, voltage minus the current that's flowing through this resistor here.
01:19
It'll be the same current through throughout the circuit.
01:24
So we can rearrange this this particular equation and solve for the internal resistance and then we find that it is the emf, the emf, minus the terminal voltage divided by the current...