In a parallel circuit, how does the current through a single branch relate to the branch's resistance?

In a parallel circuit, how does the current through a single branch relate to the branch's resistance?

• A. Higher resistance means more current
• B. Current is independent of branch resistance
• C. Higher resistance means less current
• D. The current is the same for all branches

Answer: (C)

In a parallel circuit, the current through a single branch is set by Ohm’s law: I = V/R. Because all branches share the same voltage from the source, the branch current varies inversely with that branch’s resistance. So, if a branch has higher resistance, its current is smaller; if it has lower resistance, its current is larger. The total current in the circuit is the sum of all branch currents. This explains why the statement that higher resistance means less current is the best choice. (The other ideas fail because current in a branch does depend on its resistance, and branches don’t necessarily draw the same current unless their resistances happen to be equal.)

In a parallel circuit, the current through a single branch is set by Ohm’s law: I = V/R. Because all branches share the same voltage from the source, the branch current varies inversely with that branch’s resistance. So, if a branch has higher resistance, its current is smaller; if it has lower resistance, its current is larger. The total current in the circuit is the sum of all branch currents.

This explains why the statement that higher resistance means less current is the best choice. (The other ideas fail because current in a branch does depend on its resistance, and branches don’t necessarily draw the same current unless their resistances happen to be equal.)