NEETPhysicsCurrent ElectricityMCQ+4 / −1
A uniform metal wire of length has resistance. Now this wire is stretched to a length and then bent to form a perfect circle. The equivalent resistance across any arbitrary diameter of that circle is
- A
- B
- C
- D
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Correct answer: A
$R_0=10 \Omega$
After stretching its length upto $2l$
$$\begin{aligned} R_1 \& =n^2 R_0 \\ \& =4 R_0 \\ \& =40 \Omega \end{aligned}$$

$$R_{A B}=\frac{20 \times 20}{20+20}=10 \Omega$$
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