Common Misconceptions

⚠️ Common Misconceptions

Misconception 1: "All components obey Ohm's Law"

Only ohmic conductors (like fixed resistors at constant temperature) obey Ohm's Law. Components like filament lamps, diodes, thermistors, and LDRs are non-ohmic — their resistance changes with conditions. Ohm's Law states that V ∝ I only when resistance is constant.

Misconception 2: "A thicker wire always has more resistance"

This is the opposite of the truth. A thicker wire has a larger cross-sectional area, which means more pathways for electrons to travel side-by-side. This reduces resistance. Think of a wider road allowing more traffic — it decreases congestion (resistance), not increases it.

Misconception 3: "Resistance of a metal decreases when it gets hotter"

For metals, the opposite is true: resistance increases with temperature (greater ionic vibration causes more electron collisions). It is thermistors and semiconductors that show decreasing resistance with increasing temperature. Students often confuse these two opposite behaviours.