If the voltage across a circuit remains constant ($V=constant$), how does the current ($I$) change when the resistance ($R$) is doubled?

• A. The current doubles.
• B. The current remains the same.
• C. The current is halved ($I\to \frac{I}{2}$).
• D. The current becomes zero.

Answer: (C)

Verified step by step guidance

1. Recall Ohm's Law, which relates voltage (V), current (I), and resistance (R) as: \(V = I \\times R\).
2. Since the voltage V is constant, we can express the current as: \(I = \frac{V}{R}\).
3. If the resistance R is doubled, then the new resistance becomes \$2R$.
4. Substitute the new resistance into the current formula: \(I_{new} = \frac{V}{2R}\).
5. Compare the new current \(I_{new}\) to the original current \(I\): \(I_{new} = \frac{1}{2} I\), which means the current is halved.