Two metallic wires A and B are of same material and have equal length. If the cross-sectional area of B is double that of A, then which one among the following is the electrical resistance of B?

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Q: 79 (NDA-I/2012)
Two metallic wires A and B are of same material and have equal length. If the cross-sectional area of B is double that of A, then which one among the following is the electrical resistance of B?

question_subject: 

Science

question_exam: 

NDA-I

stats: 

0,5,18,4,9,5,5

keywords: 

{'electrical resistance': [0, 0, 0, 1], 'equal length': [2, 0, 1, 2], 'same material': [0, 0, 2, 4]}

The electrical resistance of a wire depends on its length, cross-sectional area, and the material it is made of. In this question, wires A and B are made of the same material and have the same length. The only difference is that the cross-sectional area of B is double that of A.

The resistance of a wire is inversely proportional to its cross-sectional area. This means that as the cross-sectional area increases, the resistance decreases. Therefore, if the cross-sectional area of B is double that of A, then the resistance of B will be less than that of A.

Option 1 states that the resistance of B is twice that of A. This is incorrect because, according to the information given, the resistance of B should be less than that of A, not double.

Option 2 states that the resistance of B is 4 times that of A. This is incorrect because, again, the resistance of B should be less than that of A.

Option 3 states that the resistance of B is 1/4 that of A. This is incorrect because, according to the information given, the resistance of B should be less than that of A, not 1/4.

Option 4 states that the resistance of B is 1/2 that