A network contains three sequential junctions ,

PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits

Problem

A network contains three sequential junctions

P

Q

, and

R

connected by conductors. The measured branch currents (positive values indicate flow toward the junction named) are: • Junction

P

4.2\,\text{A}

enters from the left,

1.5\,\text{A}

leaves upward, and current

I_3

flows toward

Q

. • Junction

Q

3.0\,\text{A}

enters downward,

I_3

enters from

P

, and current

I_5

leaves toward

R

. • Junction

R

2.7\,\text{A}

enters from the right,

I_5

enters from

Q

, and current

I_7

leaves upward to the battery. No other currents enter or leave the circuit. Determine the magnitudes and directions of

I_3

I_5

, and

I_7