A uniform metallic wire of resistance $4 \Omega$ is bent to form a circle. What is the effective resistance between the end of its diameter?

$1 \Omega$

The correct answer is Option (1) → $1 \Omega$

When a wire is bent into circle, the current splits equally between two halves of the wire, when measured between the ends of the diameter.

$R_{half}=\frac{R}{2}=\frac{4}{2}=2Ω$

R → Resistance of wire

When connected in parallel,

$R_{eff}-R_{half}+R_{half}⇒R_{eff}=\frac{R_{half}}{2}=\frac{2}{2}$

$R_{eff}=1Ω$