A wire of uniform resistance λ Ω / m is bent into a circle of radius r and another piece of wire with length 2 r is connected between points A and B…

A wire of uniform resistance $\displaystyle \lambda \Omega / \mathrm{m}$ is bent into a circle of radius $\displaystyle r$ and another piece of wire with length $\displaystyle 2 r$ is connected between points $\displaystyle A$ and $\displaystyle B$ (AOB) as shown in figure. The equivalent resistance between points $\displaystyle A$ and $\displaystyle B$ is $\displaystyle \_\_\_\_$ $\displaystyle \Omega$.