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MHT CET Medical202623 April 2026Morning ShiftPhysicsCurrent ElectricityActual

In a potentiometer experiment, the balancing with a cell is at length 240 cm. On shunting the cell with a resistance of 2 , the balancing length becomes 120 cm. The internal resistance of the cell is

Options

  1. A1
  2. B0.5
  3. C4
  4. D2

Correct answer

D. 2

Step-by-step solution

The internal resistance r of a cell determined using a potentiometer is given by the formula: r = R ( l₁ l₂ - 1 ) Given l₁ = 240 cm, l₂ = 120 cm, and R = 2 . Substituting the values: r = 2 ( 240 120 - 1 ) r = 2 (2 - 1) r = 2 Answer: 2

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