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$\frac{R}{4}$
B$\frac{R}{8}$
C$4R$
D$\frac{R}{2}$
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A$\frac{R}{4}$
a $ \Rightarrow $ ${R_{AB}} = \frac{{R/2}}{2} = \frac{R}{4}$
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