Question map
Which one of the following formulas does not represent electrical power?
Explanation
Electrical power (P) is defined as the rate at which electrical energy is dissipated or consumed in a circuit. The fundamental formula for electric power is the product of potential difference (V) and current (I), expressed as P = VI. By applying Ohm's law (V = IR), this expression can be derived into two other equivalent forms: P = I²R and P = V²/R [1]. These three formulas (VI, I²R, and V²/R) are standard representations used to calculate power depending on whether voltage, current, or resistance is known [1]. The expression IR² is mathematically incorrect and does not represent electrical power, as power is proportional to the square of the current (I²) multiplied by the resistance (R), not the current multiplied by the square of the resistance [1].
Sources
- [1] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > What you have learnt > p. 192