What is the total current drawn from the 12 V source in the parallel circuit with a 6 Ω branch and a 3 Ω branch?

What is the total current drawn from the 12 V source in the parallel circuit with a 6 Ω branch and a 3 Ω branch?

• A. 4 A
• B. 6 A
• C. 2 A
• D. 8 A

Answer: (B)

In a parallel circuit, the full source voltage appears across every branch, so each resistor draws its own current according to I = V/R. The total current from the source is the sum of the branch currents. For the 6 Ω branch: I = 12 V / 6 Ω = 2 A. For the 3 Ω branch: I = 12 V / 3 Ω = 4 A. Add them together: 2 A + 4 A = 6 A. So the current drawn from the 12 V source is 6 A. (Equivalently, the total current can be found via the equivalent resistance: 1/R_eq = 1/6 + 1/3 = 1/2, so R_eq = 2 Ω and I = 12 V / 2 Ω = 6 A.)

In a parallel circuit, the full source voltage appears across every branch, so each resistor draws its own current according to I = V/R. The total current from the source is the sum of the branch currents.

For the 6 Ω branch: I = 12 V / 6 Ω = 2 A.

For the 3 Ω branch: I = 12 V / 3 Ω = 4 A.

Add them together: 2 A + 4 A = 6 A.

So the current drawn from the 12 V source is 6 A. (Equivalently, the total current can be found via the equivalent resistance: 1/R_eq = 1/6 + 1/3 = 1/2, so R_eq = 2 Ω and I = 12 V / 2 Ω = 6 A.)