Question

6. Find specific resistance of a wire whose length is 5m radius of wire is 7cm and resistance of
the wire is 50 ohm.​

Answer 1

$\huge \bf{Answer} \\ = 15.4 \mho \: cm \\ \\ \huge \bf{Solution} \\ \\Resistance =50\mho,\\ length \: = 5\: m \\ radius \: = 7 \: cm \: \red{\therefore \: diameter = 3.5 \: cm} \\ \\ \bf{area \: of \: cross \: sectinonal}\:A = \pi \: {r}^{2} \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{22}{7} \times 49 = 154 \\ \\ specific \: \:resistance \: is \: \rho = \frac{RA}{L} \\ \\ \implies \frac{50 \times 154}{5 \times 100} \\ \\ \implies \:\green{ \boxed{15.4 \: ohm \: cm}}$