Two wires are made having same length I and area of cross-section A. Wire 1 is made of copper and wire 2 is made of aluminium. It is given that the electrical conductivity of copper is more than that of aluminium. In this context, which one of the followi

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Q: 12 (CDS-II/2017)
Two wires are made having same length I and area of cross-section A. Wire 1 is made of copper and wire 2 is made of aluminium. It is given that the electrical conductivity of copper is more than that of aluminium. In this context, which one of the following statements is correct?

question_subject: 

Science

question_exam: 

CDS-II

stats: 

0,16,11,5,16,4,2

keywords: 

{'electrical conductivity': [0, 0, 0, 1], 'resistance': [0, 0, 1, 2], 'wires': [0, 0, 1, 1], 'same current': [0, 0, 0, 2], 'wire': [0, 0, 7, 16], 'copper': [1, 0, 1, 1], 'same length': [0, 1, 0, 2], 'aluminium': [1, 0, 3, 2]}

The correct answer is option 2 - The resistance of wire 2 will be higher than that of wire 1.

The electrical resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Therefore, if two wires have the same length and different cross-sectional areas, the wire with a smaller cross-sectional area will have a higher resistance.

In this scenario, wire 1 is made of copper, which has a higher electrical conductivity compared to aluminium, the material of wire 2. Since electrical conductivity is the reciprocal of electrical resistance, copper will have a lower resistance compared to aluminium for the same length and cross-sectional area.

Thus, wire 2, made of aluminium, will have a higher resistance than wire 1 made of copper.

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