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One wire has a cross-sectional area of 1,250 circular mils and a resistance of 7 ohms. a second piece of wire, identical except for cross-sectional area, has a resistance of 10 ohms. determine what the cross-sectional area of this second wire is. (cross-sectional area and resistance are inversely proportional.)

Respuesta :

As we know that resistance of the wire depends upon the area, length and its material

its formula is given by

[tex]R = \rho \frac{L}{A}[/tex]

so from above we can say that

Since all other parameters are same except area of the wire so we can say

[tex]\frac{R_1}{R_2} = \frac{A_2}{A_1}[/tex]

[tex]\frac{7}{10} = \frac{A_2}{1250}[/tex]

[tex]A_2 = 875 circular mils[/tex]

So area of 2nd wire is less than the first wire and its magnitude is 875 circular mils.

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