Home » Ask Physics » Change in Resistance due to stretching a wire

### Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 3,066 other subscribers

# Change in Resistance due to stretching a wire

Share with:

Sreshtha asked:

“A piece of wire is redrawn without any change in volume so that its radius become half the original. Compare the new resistance with the original value.”

Answer:

When we redraw the wire, the volume remains constant and the resistivity also remains constant. SO, the variables are

1. area of cross section and
2. the length

When radius becomes half, the area of cross section increases in such a way that A1l1 = A2l2. This implies that when length is halved, area of cross section is doubled.

We know that $\large \inline \fn_cs R=\frac{\rho l}{a}$

Therefore, the new resistance becomes (1/4) th the original value.

So, R2:R1 = 1:4

### Ask a Doubt

Post your Physics Doubts here

Name (required)

Email (required)

Subject

Message/Doubt/Question

Upload a file if required

### Half Yearly Exam Count Down

Half Yearly Exam Count Down KVS Ernakulam RegionOctober 17th, 2017
The Half Yearly Examination for Kendriya Vidyalayas of Kerala starts from 17 October 2017