Two copper conductors have equal lengths. The cross-sectional area of one conductor is four times that of the other. If the conductor with a smaller cross-sectional area has a resistance of 40 ohms, then the resistance of the other conductor will be?
Correct answer: D. 10 ohm
- A. 160 ohm
- B. 80 ohm
- C. 20 ohm
- D. 10 ohm
Explanation
Since both conductors are made from copper, their resistivity ρ is the same. Both conductors are of equal lengths so l is also the same. Resistance is inversely proportional to cross sectional area. The question can be solved as follows:
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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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