To compare EMF of two cells using potentiometer the balancing lengths obtained are 200 cm and 150 cm. The least count of scale is 1 cm. The percentage error in the ratio of EMFs i $s____$
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To compare EMF of two cells using potentiometer the balancing lengths obtained are 200 cm and 150 cm. The least count of scale is 1 cm. The percentage error in the ratio of EMFs i s____

G1 Physics · Accepted Answer

For a potentiometer, E ∝ ℓ. Therefore, E₁/E₂ = ℓ₁/ℓ₂. For a quotient, the maximum fractional error is Δ(E₁/E₂)/(E₁/E₂) = Δℓ₁/ℓ₁ + Δℓ₂/ℓ₂. Using the least count of 1 cm as the maximum error in each balancing length, percentage error = [1/200 + 1/150]×100. Therefore, percentage error = [(3+4)/600]×100 = 7/6 % ≈ 1.17%. None of the printed options matches this value. The supplied source therefore marks this question as Bonus, while showing NTA answer option (2). Calculated answer: 1.17%. Importer n…