Physics

Problem

A resistor allows a current of

0.20\,\text{A}

to flow when a potential difference of

5.0\,\text{V}

is applied. What potential difference is needed to produce a current of

0.50\,\text{A}

through the same resistor? a)

5.0\,\text{V}

12.5\,\text{V}

2.0\,\text{V}

31.3\,\text{V}

Intuitive explanation

The key is recognizing that a resistor's resistance stays constant—it's a material property that doesn't change. Use Ohm's law ( $V = IR$ ) to first find the resistance from the initial conditions, then apply that same resistance to find the new voltage needed for the larger current. Since resistance is fixed, a proportionally larger current requires a proportionally larger voltage.

Intuitive explanation

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