JEE Main 2024 Physics question

To measure the internal resistance of a battery, potentiometer is used. For R = 10 Ω, the balance point is observed at ℓ = 500 cm and for R = 1 Ω the balance point is observed at ℓ = 400 cm. The internal resistance of the battery is approximately:

• (A)0.2 Ω
• (B)0.4 Ω
• (C)0.1 Ω
• (D)0.3 ΩCorrect