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MHT CET202124 Sep 2021Morning ShiftPhysicsCurrent ElectricityActual

To determine the internal resistance of a cell by using a potentiometer, the null point is at 1 ~m , when shunted by 3 resistance and at a length 1.5 ~m , when cell is shunted by 6 resistance. The internal resistance of the cell is

Options

  1. A1
  2. B4
  3. C2
  4. D6

Correct answer

D. 6

Step-by-step solution

aligned & r = R ( ₁ ₂ -1 )= R ^ ( ₁ ₂^ -1 ) & ₂=1 ~m , ₂^ =1.5 ~m R =3 , R ^ =6 & 3 ( ₁ 1 -1 )=6 ( ₁ 1.5 -1 ) aligned Solving we get ₁=3 ~m r =3 ( 3 1 -1 )=3 2=6

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