A wire of resistance 4 R is bent in the form of a circle. The equivalent resistance between two points diametrically opposite on the circle will be
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \( R \)
Two diametrically opposite points divide the circle into two equal halves. Resistance is proportional to length, so each half has resistance \( 4R/2 = 2R \), and the two halves are joined in parallel between the two points.
\( \displaystyle R_{\mathrm{eq}} = \frac{2R \times 2R}{2R + 2R} = \frac{4R^{2}}{4R} = R \)