The V–I graph of a nichrome wire is found to be a straight line passing through the origin. What two conclusi…

Question

The V–I graph of a nichrome wire is found to be a straight line passing through the origin. What two conclusions can you draw about the electrical nature of the conductor from this observation?

Accepted Answer

## Model Answer From the straight-line V–I graph passing through the origin, two conclusions are: 1. **Ohm's law is obeyed**: The potential difference (V) across the nichrome wire is directly proportional to the current (I) through it (V ∝ I), as the ratio V/I remains constant. 2. **The resistance is constant**: Since V/I = R = constant, the resistance of the nichrome wire does not change with varying current or voltage (at constant temperature). *Source: Chapter 11, Section 11.4 – Ohm's Law* ## Explanation Examiners expect two distinct, clearly stated points. The key ideas are: (i) direct proportionality → Ohm's law is followed, and (ii) the constant slope of the line means resistance is fixed. Avoid vague statements like "it's a good conductor" — stick to what the graph directly tells you.

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