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A regular hexagon is formed by six wires each of resistance r Ω and the corners are joined to centre by wires of same resistance. If the current enters at one corner and leaves at the opposite corner, the equivalent resistance of the hexagon between the two opposite corners will be (1) 4r/5 (2) 5r/8 (3) 3r/4 (4) 3r/5
- (1) 4r/5
- (2) 5r/8
- (3) 3r/4
- (4) 3r/5
Correct answer: (1) 4r/5
Solution
The correct option is 4r/5 because when the current enters at one corner and exits at the opposite corner, the symmetry of the hexagon allows us to simplify the circuit. The resistances in parallel and series combine in such a way that the total equivalent resistance calculated results in 4r/5.
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