Question

By fixing the voltage across the rheostat, the current through becomes inversely proportional to the resistance. This is accordance to which law?

• A. Ohm's law
• B. Bio-Savart's law
• C. Gauss Law
• D. This situation is not possible

Answer 1

Answer: (A)

Ohm's law

As per Ohm's law, $V=IR$, where $V$ is voltage, $I$ is current and $R$ is resistance. We have $I=\frac{V}{R}$. By fixing $V$, it becomes constant. Hence $I\propto \frac{1}{R}$. Biot-Savart law and Gauss law do not provide any relation among $V,I$ & $R$.