Q.

A wire of uniform resistance λ Ω/m is bent into a circle of radius r and another piece of wire with length 2r is connected between points A and B (AOB) as shown in the figure. The equivalent resistance between points A and B is _______ Ω.               [2026]

1 2πλr  
2 3πλr8  
3 6πλr3π+16  
4 (π+1)2rλ  

Ans.

(3)

1RAB=2λπr+1λ·2r+2λ·3πr

=1λr[2π+12+23π]

=1λr(12+3π+46π)=1λr(16+3π6π)

RAB=λr(6π16+3π)