A metallic wire of length 1m and diameter 1mm has a resistance of `2 Omega ` .Calculate the resistance of a wire of same material and length having a diameter of 2 mm .

Explanation

Given , the wires are of same material and length
So, resistance , `R prop 1/A`
` :. " "(R_(1))/(R_(2)) =(A_(2))/(A_(1))=((d_(2))/(d_(1)))^(2)` (1)
` :. A prop "(diameter )"^(2)`
` :. " " R_(2)=R_(1) ((d_(1))/(d_(2)))^(2) = 2xx(1/2)^(2)= 0.5 Omega `(1)