Question

A wire of resistance 10 ohm is bent in the form of a closed circle. What is the effective resistance between the two points at the end of any diameter of the circle?

• A. 0.4 ohm
• B. 0 ohm
• C. 2.5 ohm
• D. 10 ohm

Answer 1

The correct option is C 2.5 ohm

As the wire is bent at its mid point, thus resistance of each semi-circle $R=\frac{10}{2}=5\Omega$

Effective resistance between A and B $R_{eff}=5\Omega ||5\Omega$

$⟹$ $R_{eff}=\frac{5\times 5}{5+5}=2.5\Omega$