Question

if 4 ohm resistor is doubled on it. Calculate the new resistance of the wire.​

Answer 1

Answer:

1 ohm

Explanation:

if 4 ohm wire is doubled on itself then its length will decrease by twice, causing resistance two decrease by twice and the area of cross section will be doubled causing the resistance to decrease by twice. As a result total decrease in resistance = 1/4 times

therefore, new resistance =( 4 * 1/4 ) ohms

= 1 ohm

Answer 2

Answer:

Consider: resistor is doubled on it. It means to fold it. There is no change in the volume.

What it means: length halved, and area of cross section doubled.

Given:

R = p l/A = 4Ω  (where p = Rho)

p' = p

l' = l / 2

A' = 2A

Calculation:

R' = p' l'/A'

= p (l /2) ÷ 2A

= 1/4 (p l / A)

= 1/4R

= 1/4 × 4

= 1Ω

Hpe it helps :)