Three defrost heaters, each 15 ohms, are wired in parallel to a 120 volt power supply. What is the total current drawn by the heaters?

Three defrost heaters, each 15 ohms, are wired in parallel to a 120 volt power supply. What is the total current drawn by the heaters?

• A. 12 A
• B. 18 A
• C. 24 A
• D. 6 A

Answer: (C)

In a parallel circuit, the full supply voltage appears across each path, and the currents in each path add up to give the total current. Here, three heaters are connected in parallel to 120 V, each with a resistance of 15 Ω. Current through one heater = V/R = 120 V / 15 Ω = 8 A. Since there are three heaters in parallel, the total current drawn is 3 × 8 A = 24 A. A quick check uses the equivalent resistance for three equal resistors in parallel: R_eq = 15 Ω / 3 = 5 Ω. Then I_total = V / R_eq = 120 V / 5 Ω = 24 A, confirming the result. So, the total current drawn by the heaters is 24 A.

In a parallel circuit, the full supply voltage appears across each path, and the currents in each path add up to give the total current. Here, three heaters are connected in parallel to 120 V, each with a resistance of 15 Ω.

Current through one heater = V/R = 120 V / 15 Ω = 8 A. Since there are three heaters in parallel, the total current drawn is 3 × 8 A = 24 A.

A quick check uses the equivalent resistance for three equal resistors in parallel: R_eq = 15 Ω / 3 = 5 Ω. Then I_total = V / R_eq = 120 V / 5 Ω = 24 A, confirming the result.

So, the total current drawn by the heaters is 24 A.