Question

A copper wire has diameter 0.5 mm and resistivity 1.6 into 10 to the power 8 ohm what will be the length of this wire to make resistance 10 ohm how much the resistance to change if the diameter is doubled

Answer 1

Area of cross-section of the wire, A =? (d/2) 2  

Diameter= 0.5 mm = 0.0005 m  

Resistance, R = 10 ?

We know that  

? length of the wire = 122.72m