In the circuit with a 30 V source across 8 Ω and 12 Ω in parallel, what is the voltage across the 12 Ω resistor?

In the circuit with a 30 V source across 8 Ω and 12 Ω in parallel, what is the voltage across the 12 Ω resistor?

• A. 15 V
• B. 30 V
• C. 20 V
• D. 40 V

Answer: (B)

In a parallel circuit, every branch shares the same voltage as the source. Since the 8 Ω and 12 Ω resistors are in parallel across a 30 V source, the 12 Ω resistor also has 30 V across it. The other voltages listed would not occur with this configuration and a 30 V supply, so 30 V is the correct reading.

In a parallel circuit, every branch shares the same voltage as the source. Since the 8 Ω and 12 Ω resistors are in parallel across a 30 V source, the 12 Ω resistor also has 30 V across it. The other voltages listed would not occur with this configuration and a 30 V supply, so 30 V is the correct reading.