Question

A piece of wire of resistance 4 ohm is bent through 180 at its mid point and the two halves are twisted together. Then the resistance is

• A. 8 ohms
• B. 1 ohm
• C. 2 ohms
• D. 5 ohms.

Answer 1

Answer: (B)

1 ohm

Answer 2

Length is halved. Area is doubled. Since $R = \frac{\rho \, l}{A}$ . Therefore R will become $\left( \frac{1}{4} \right)$ times.