Question:
A metal wire of resistance $3 \Omega$ is elongated to make a uniform wire of double its previous length. This new wire is now bent and the ends joined to make a circle. If two points on the circle make an angle $60^{\circ}$ at the centre, the equivalent resistance between these two points will be:
Correct Option: , 3
Solution:
(3) When length becomes double its resistance becomes
$\left(R \propto l^{2}\right)$
$R=4 \times 3=12 \Omega$
$R_{\mathrm{eq}}=\frac{2 \times 10}{12}=\frac{5}{3} \Omega$
