A uniform metal wire of length $l$ has 10 Ω resistance. Now this wire is stretched to a length $2l $ and then bent to form a perfect circle. The equivalent resistance across any arbitrary diameter of that circle is :

Question

An infinitely long straight wire carrying current $I$ is bent in a planar shape as shown in the diagram. The radius of the circular part is $r$. The magnetic field at the centre $O$ of the circular loop is :

Answer 1

Initial resistance, R₀, is 10 Ω. Upon stretching to length 2l, the resistance R₁ becomes $\frac{2l}{l}$R₀ = 20 Ω. Bending into a circle does not alter the total resistance, which remains 20 Ω.

The resistance of a semi-circle along any diameter is calculated as 20/2 = 10 Ω.

List I	List II
A. The Evil Quartet	III. Causes of biodiversity losses
B. Ex situ conservation	I. Cryopreservation
C. Lantana camara	II. Alien species invasion
D. Dodo	IV. Extinction

A uniform metal wire of length \(l\) has 10 Ω resistance. Now this wire is stretched to a length \(2l \) and then bent to form a perfect circle. The equivalent resistance across any arbitrary diameter of that circle is :

The Correct Option is A

Solution and Explanation

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