A nichrome wire has a resistance of 10, Omega | vedclass

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Question

(A) The resistance $(R)$ of a wire is given by the formula $R = \rho \frac{l}{A}$,where $\rho$ is the resistivity,$l$ is the length,and $A$ is the are

Vedclass · Accepted Answer

$7.5\, \Omega$

Vedclass · Answer

(A) The resistance $(R)$ of a wire is given by the formula $R = ho \frac{l}{A}$,where $ho$ is the resistivity,$l$ is the length,and $A$ is the area of cross-section.For the first wire,$R_1 = 10\, \Omega = ho \frac{l}{A}$.For the second wire,the length $l' = 3l$ and the area $A' = 4A$.The resistance of the second wire is $R_2 = ho \frac{l'}{A'} = ho \frac{3l}{4A}$.Substituting the value of $R_1$ into the equation,we get $R_2 = \frac{3}{4} 	imes R_1$.$R_2 = \frac{3}{4} 	imes 10\, \Omega = 7.5\, \Omega$.

$A$ nichrome wire has a resistance of $10\, \Omega$. Find the resistance of another nichrome wire,whose length is three times and area of cross-section four times the first wire.

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