Question

A wire of resistance 4 ohm is stretched to double its length . Find its new resistance

Answer 1

Hope this helps you...:-)))

Answer 2

The “resistance of a wire” after stretched is 16 ohm.

Given:

Resistance of wire (r) = 4 ohm

Stretched to twice of its length.

To find:

The resistance of the wire after stretching (R) = ?

Solution:

The resistance of the wire is “directly proportional to” the square in length of wire.

So, if the length is stretched to twice then the resistance gets multiplied by four times.  

$R=4 r$

$R=4 \times 4$

$R=16 \ \text{ohm}$