The power dissipated in a 10Ω resistor carrying 2A is:

## The reasoning Power dissipation in a resistor follows the formula **P = I²R** (Power equals current squared times resistance). Here's the working: - Current I = 2A - Resistance R = 10Ω - P = I²R = (2)² × 10 = 4 × 10 = **40 W** You could also use P = V²/R or P = VI, but you'd first need to find voltage using Ohm's law (V = IR = 2 × 10 = 20V). Then P = 2A × 20V = 40W. Same answer! ## Why the wrong options tempt you **A) 10W** — You just multiplied I × R (2 × 10), forgetting to *square* the current first. **B) 20W** — You calculated V = IR = 20V correctly, but then mistook voltage for power. Voltage and power are different quantities! **D) 200W** — You might have done (I × R)² = (20)² = 400, then divided randomly, or mixed up your formulas entirely. ## Quick takeaway For power in resistors, always remember: **"I-squared-R"** — square the current first, then multiply by resistance. It's the most direct route when current is given!