Question

a given wire of resistance 1 ohm is strecthed to double its lenght . find new resistance

Answer 1

Hi friend,

Hope the attachment helps u..

Answer 2

since the wire has 1ohm resistance.
therefore the resistance provided by the particles or the electrons is 1ohm
since the resistivity depends on length of object(one of the factors)----  R           inversely proportional to length of object(wire)
 
so the new R =1/2 ohm