A metal wire of resistance 3Ω is elongated to make a uniform wire of double its previous length. This new wire is now bent and the ends joined to make a circle. If two points on this circle make an an

Question

A metal wire of resistance 3Ω is elongated to make a uniform wire of double its previous length. This new wire is now bent and the ends joined to make a circle. If two points on this circle make an angle 6 0 o at the center, the equivalent resistance between these two points will be:

TestHub · Accepted Answer

We know, R = A ρl ​ = A l ρ l 2 ​ = V o l u m e ρ l 2 ​ R ∝ l 2 , if the volume is constant. ∴ New resistance = 4 R R 1 ​ = 360 4 R ​ × 300 = 3 10 R ​ R 2 ​ = 360 4 R ​ × 60 = 3 2 R ​ ∴ Equivalent resistance R e q ​ = R 1 ​ + R 2 ​ R 1 ​ R 2 ​ ​ = 3 10 R ​ + 3 2 R ​ 3 10 R ​ × 3 2 R ​ ​ = 9 5 R ​ = 3 5 ​ Ω

Physics - Current Electricity Question with Solution | TestHub

Options:

Doubts & Discussion