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JEE Main 2023 (1 Feb, Shift 1) · Combination of Resistors

Combination of Resistors question from JEE Main 2023 (1 Feb, Shift 1)

Q34JEE Main 2023 · 1 FEB · SHIFT 1Medium

Combination of Resistors

The equivalent resistance between AA and BB of the network shown in figure;

Figure

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Answer: (b)

  1. Redraw as a Wheatstone bridge: arms RR and 3R3R on one side, 2R2R and 6R6R on the other, with 9R9R as the bridge.
  2. R3R=2R6R\dfrac{R}{3R} = \dfrac{2R}{6R}, so the bridge is balanced and 9R9R carries no current.
  3. RAB=(R+3R)∥(2R+6R)=4R×8R12R=8R3R_{AB} = (R + 3R) \parallel (2R + 6R) = \dfrac{4R \times 8R}{12R} = \dfrac{8R}{3}
  4. So the answer is (b) 83R\dfrac{8}{3}R.
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