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When two cells are connected in series i.e., (E₁ + E₂) the balance point is at 50 cm. And when two cells are connected in opposite direction i.e., (E₁ - E₂) the balance point is at 10 cm. According to principle of potential, E₁ + E₂ = 50/10 and E₁ - E₂ = 10/50.

1. E₁/E₂ = 3/2
2. E₁/E₂ = 2/3
3. E₁/E₂ = 1/2
4. E₁/E₂ = 2

Correct answer: E₁/E₂ = 3/2

Solution

Using the principle of potentiometer, the ratio of the balance points corresponds to the ratio of the EMFs. From the given equations, E₁ + E₂ = 50/10 = 5 and E₁ - E₂ = 10/50 = 0.2. Solving these two equations simultaneously, we get E₁ = 1.8 and E₂ = 1.2. Thus, E₁/E₂ = 1.8/1.2 = 3/2.

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