Question

A wire of given material having length L & area of cross section A has a resis tance of 4 ohm What would be the resistance of onether wire of same material having length L/2 & area of cross section ?????​

Answer 1

In 1st case,

length=L area=A

R1= 4ohm

p= R1 ❌ a/l1

=4A/ L

In 2nd case ,

length =L/2. area=A

Resistance = R2

p = R2 ❌ a/ l2

= R2 ❌ A ➗ L/2

As both wires are made of same material , so specific resistance p is same

Then,

4A /L =R2❌A / L/2

2❌R2 =4

R2 = 2 ohm [answer]

Thank you!