Three wires are connected at a junction. One of the wires carries a current of 4 A into the junction, while another carries 5 A into the junction. What is the current in the third wire?
A) 4 A away from the junction
B) 9 A away from the junction
C) 4 A into the junction
D) 9 A into the junction
E) 1 A away from the junction

Question

Quizplus · Accepted Answer

According to the principle of conservation of charge, the total current entering a junction must equal the total current leaving the junction. Here, 4 A + 5 A = 9 A enters the junction, so 9 A must leave the junction through the third wire.

Three Wires Are Connected at a Junction