At a junction, branch currents are 5 A and 3 A entering the node. If a third branch carries current away from the node, what is its current magnitude?

At a junction, branch currents are 5 A and 3 A entering the node. If a third branch carries current away from the node, what is its current magnitude?

• A. 8 A flowing out of the node
• B. 2 A flowing into the node
• C. 5 A flowing out of the node
• D. 3 A flowing into the node

Answer: (A)

Kirchhoff's current law says that the total current into a junction must equal the total current leaving it. The two branches bring in 5 A and 3 A, which adds up to 8 A entering the node. Since the third branch carries current away from the node, it must take out 8 A to balance what comes in. Therefore, the current magnitude is 8 A, flowing out of the node. Other options would not maintain both the needed balance and the specified direction.

Kirchhoff's current law says that the total current into a junction must equal the total current leaving it. The two branches bring in 5 A and 3 A, which adds up to 8 A entering the node. Since the third branch carries current away from the node, it must take out 8 A to balance what comes in. Therefore, the current magnitude is 8 A, flowing out of the node. Other options would not maintain both the needed balance and the specified direction.