Question

ifa wire of resistanceis 6 ohm is fulted frommidpoint so thatits lengthbecomes half then what is new resistance

Answer 1

it would be reduce by 4 times

Answer 2

Resistance= Resistivity x length/area

When the wire is stretched to double the length , the area of cross section gets reduced to half.

So

New Resistance = Resistivity x 2length/area/2

I.e,

New resistance = (Resistivity x area/length)x4

i.e, New resistance = Resistance x 4

So when the wire is stretched, the resistance multiplies by four times. 

since the resistance is 6 ohm new resistance is 6*4=24ohm