Question

Resistance of a wire is doubled and then what is the change in length and constant area of cross section?​

Answer 1

length increases root 2 times and area decreases root 2 times

Answer 2

let length be l crossection be a and density be q

we know that

R=ql/a

final

2R=ql/a

so

R/2R=ql(initial)/a/ql(final)/a

l initial /l final =1/2

l final =2* length of wire in initial