Question

Apply the junction rule at point a in Figure 21.55.

Question Image

Final Answer

$I_3 = I_1 + I_2$

Solution Video

#### Sign up to view this solution video!

View sample solutionVideo Transcript

This is College Physics Answers with Shaun Dychko.
The Junction Rule says that all the currents going into a point equals the sum of all the currents leaving that point or that junction. And so this junction here has a current

*I3*going into it. So we have the total of all the currents going in of which there’s only one, so it’s*I3*equals the total of the currents coming out which is*I1*and*I2*. So there’s our Junction Rule written out separately.