Define electric power. When do we say that the power consumed in an electric circuit is 1 watt ?
Generated by claude-sonnet-4-6 · 2026-06-15 06:42 · grounding rag
Model Answer
Electric power is the rate at which electric energy is dissipated or consumed in an electric circuit. It is given by:
$$P = VI = I^2R = V^2/R$$
The SI unit of electric power is watt (W).
The power consumed in a circuit is said to be 1 watt when a current of 1 ampere flows through it at a potential difference of 1 volt.
$$1 \text{ W} = 1 \text{ V} \times 1 \text{ A}$$
Source: Chapter 11, Section 11.8
---
Explanation
- The definition should mention "rate of consumption/dissipation of energy."
- For the second part, examiners expect the specific condition: 1 A current at 1 V potential difference. State the formula $1\text{ W} = 1\text{ VA}$ for full marks.
- Both marks are straightforward: 1 mark for definition + formula, 1 mark for the condition for 1 watt.