The length and area of cross-section of a cop | vedclass

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Question

(C) 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 area

Vedclass · Accepted Answer

$0.85$

Vedclass · Answer

(C) 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.Given:Resistivity $ho = 1.7 	imes 10^{-8} \ \Omega \ m$Length $L = 30 \ m$Area $A = 6 	imes 10^{-7} \ m^2$Substituting these values into the formula:$R = (1.7 	imes 10^{-8} \ \Omega \ m) 	imes \frac{30 \ m}{6 	imes 10^{-7} \ m^2}$$R = 1.7 	imes 10^{-8} 	imes 5 	imes 10^7 \ \Omega$$R = 8.5 	imes 10^{-1} \ \Omega$$R = 0.85 \ \Omega$Therefore,the correct option is $C$.

The length and area of cross-section of a copper wire are respectively $30 \ m$ and $6 \times 10^{-7} \ m^2$. If the resistivity of copper is $1.7 \times 10^{-8} \ \Omega \ m$,then the resistance of the wire is (in $Omega$)

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