What is the voltage across each resistor connected in parallel to a 12-volt battery?

• A. 6 volts
• B. 12 volts
• C. 24 volts
• D. It depends on resistor value

Answer: (B)

When resistors are connected in parallel to a voltage source, each branch is attached across the same two points, so they all share the same voltage as the source. With a 12-volt battery, each resistor in parallel sees 12 volts across it, regardless of its individual resistance.

The value of each resistor only determines how much current flows through that branch (Ohm’s law: I = V/R). So a lower resistance draws more current, a higher resistance draws less, but the voltage across every branch remains 12 volts.

The other ideas don’t fit this setup: 6 volts would come from a division of voltage in series, not parallel. 24 volts would require two 12-volt sources in series. Saying it depends on the resistor value would imply the voltage changes by resistor, which isn’t the case in an ideal parallel arrangement where the source fixes the voltage.