Question

The resistivity of a given wire of cross sectional area 0.7mm is 4.9*10-4mm.Calculate the resistance of 2m length of the wire

Answer 1

Answer:
`1.4\ \Omega`

Step-by-step explanation:

Given

Cross-sectional area
`A=0.7\ mm^2`

Resistivity
`\rho =4.94* 10^(-4)\ \Omega-mm`

Length of wire
`l=2\ m\ or\ 2000\ mm`

Resistance is given by

`\Rightarrow R=(\rho l)/(A)\\\\\text{Insert values}\\\\\Rightarrow R=4.9* 10^(-4)* (2000)/(0.7)\\\\\Rightarrow R=1.4\ \Omega`