At a junction

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits

Problem

At a junction, currents

I_1=3\,\text{A}

and

I_2=2\,\text{A}

enter, while current

I_3

leaves. Using the sign convention that currents entering are positive, which equation correctly applies Kirchhoff’s current law? (a)

I_1+I_2+I_3=0

(b)

-I_1-I_2+I_3=0

(c)

I_1+I_2-I_3=0

(d)

I_1-I_2+I_3=0