Question

1- a wire of length 200m and area of cross section 1mm^2 has a resistance of 2k ohm find the resistivity of the material 2- resistance of a metallic wire is 40 ohms what will be the rsistance of another wire of same material with the same length and on third the area of cross section of the first wire?

Answer 1

Answer:1)R=PL/A

P=resistivity

P=RA/l

P=2×10³×10^-6/200

P=10^-2mm

P=0.01mm

2)R1/R2=1/3A1/A1

40/R2=1/3

R2=120Ω

Explanation: