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MHT CET202013 Oct 2020Evening ShiftPhysicsCurrent ElectricityActual

In potentiometer experiment, the balancing length with a cell E ₁ of unknown e.m.f. is ₁ ^ cm . By shunting the cell with resistance R , the balancing length becomes ₁ 2 ~cm , the internal resistance (r) of a cell is

Options

  1. Ar =0
  2. Br= R 2
  3. Cr =2 R
  4. Dr = R

Correct answer

D. r = R

Step-by-step solution

r = R ( ₁ ₂ -1 ) ₂= ₁ 2 Putting the values and solving we get r=R

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