Question

A uniform wire of resistance 36 W is bent in the form of a circle. The effective resistance between A and B is (O is the centre of circle):

• A. 2.75 W
• B. 3 W
• C. 33 W
• D. 36 W

Answer 1

Answer: (A)

2.75 W

Answer 2

R₁ 2pr length of wire has resistance = 36 W

\ rp/6 length of wire has resistance =$\frac{36}{2\pi r}$×$\frac{r\pi}{6}$ = 3 W

\ R₁ = 3W \ R₂ = 33W

R_eq = $\frac{3 \times 33}{3 + 33}$ = $\frac{3 \times 33}{36}$ 2.75