Ohm's Law is an empirical relationship often written as . It is a very useful model in circuit analysis. Which statement best describes the applicability of Ohm's Law?
- It is a fundamental law of physics, universally applicable to all materials that conduct electricity.
- It accurately describes materials for which the ratio of potential difference to current is constant over a wide range of conditions. (correct answer)
- It is valid only for direct current (DC) circuits and cannot be used for alternating current (AC) circuits.
- It applies only to pure elemental metals, and not to alloys or semiconductor materials.
Explanation: Ohm's Law is not a fundamental law but an empirical model that holds true for certain materials, called ohmic materials. For these materials, the resistance is constant over a range of voltages and temperatures. Many materials, such as semiconductors and insulators, do not follow this linear relationship.