AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Using Ohm's law: $R = \dfrac{V}{I} = \dfrac{12 \text{ V}}{3 \text{ A}} = 4\ \Omega$
The resistance of the resistor is 4 Ω.
Source: Chapter 11, Ohm's Law
This is a direct application of Ohm's law: $V = IR$, so $R = V/I$. Always write the formula, substitute values with units, and state the final answer with the correct SI unit (Ω). Examiners award the mark for the correct substitution and answer.