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A nichrome wire $1 m$ long and $1 mm^2$ in cross-section area draws 4 ampere at 2 volt. The resistivity of nichrome is |
$1 × 10^{-7}Ω-m$ $2 × 10^{-7}Ω-m$ $4 × 10^{-7}Ω-m$ $5 × 10^{-7}Ω-m$ |
$5 × 10^{-7}Ω-m$ |
Resistance = $\frac{V}{I}$ = 0.5 A R = $\frac{\rho l}{A}$ = 0.5 A $\rho = \frac{0.5 \times 10^{-6}}{1} = 5 \times 10^{-7}\Omega$-m |
