Question

If a wire of resistance 1 ohm is stretched to double it's lenght then the resistance will become please answer me the perfect answer​

Answer 1

Answer:

4ohm

Explanation:

The point here to understand is when we stretch a wire we increase is its length and as the volume of the wire is kept constant, so the area of the cross-section of the wire has to be now exactly half of the initial value.

Now let us say the original length of wire is '1',the area of cross-section of the wire is 'A' and the resistivity of the wire is 'P', then acc. to the formula for resistance

R=P*(I/A)

Now after stretching the wire,

Length=2*l Area=A/2

So the new resistance

R'=P*[21/(A/2)]

R'=4*[P*(I/A)]

R'=4R

So the new resistance is 4 times the initial resistance.

Answer 2

Answer:

hii good morning

kaise ho app