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2 years ago

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A tungsten wire has resistance R at 20°C. A second tungsten wire at 20°C has twice the length and half the cross-sectional area

of the first wire. In terms of R, the resistance of the second wire is
(1)R/2
(2)2R
(3)R
(4)4R

1 answer:

Bad White [126]2 years ago

6 0

The resistance is 4 times the resistance of the first wire. the formula is R = p*l/A with p being resistivity, l length and A area. So if you double length and half area, which botv result in more resistance, you get p*2/0.5 or 4 (p can be abandoned because it is the same. We take standard length and area as 1)

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