# Kirchoff's Rules

This is a question about Kirchoff's rules.

Consider the group of resistors shown in the attachment, where R1 = 4.0 ohms and E = 9.1 V.

Find the current in each resistor.

And determine the potential difference between points A and B.

Please see attached for diagram.

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Can someone please show me how to go about doing the following problem?

Consider the group of resistors shown in Figure 21-37, where R1 = 4.0 and = 9.1 V.

Find the current in each resistor.

And determine the potential difference between points A and B.

Thank you!

Kirchoff rules:

1. The sum of the currents going into a junction is zero

2. The sum of potentials in any closed circuit is zero.

Now we have to see how we go about implementing them. For this we need to use conventions.

The first convention is: a current going into a junction is positive, while a current coming out is negative.

In the junction above, I1 is going in therefore in the junction equation it will have a positive sign, while I2 and I3 will have negative signs, since they are coming out. So according to the first rule:

This is simply the rule "what comes in must come out".

The second convention is that if the direction loop exits the positive end of the battery, the battery potential in the equation is positive. The sign potential on a resistor is determined by the ...

#### Solution Summary

The solution supplies an attachment containing the full written explanation of how to apply Kirchoff's rules to the group of resistors described, complete with helpful diagrams.