Question

When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between any two of diametrically opposite points will be

• A. R/4
• B. 4R
• C. R/8
• D. R/2

Answer 1

Answer: (A)

R/4

Answer 2

Both are in parallel.
$\frac{1}{R'}=\frac{2}{R}+\frac{2}{R}=\frac{4}{R} \, \, \Rightarrow\, \, R' = \frac{R}{4}.$