Which of the following materials has a negative temperature co-efficient of resistance?
Correct answer: B. Carbon
- A. Copper
- B. Carbon
- C. Aluminum
- D. Brass
Explanation
The correct answer is option B: Carbon. Carbon can exhibit a negative temperature coefficient of resistance, meaning that its resistance decreases as temperature rises. This is due to the nature of carbon's bonding and structure, which can allow for increased electron mobility at higher temperatures under certain conditions. The other materials listed-copper, aluminum, and brass-all have positive temperature coefficients of resistance, meaning their resistance increases with rising temperature.
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About Current Electricity
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
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