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Physics · PYQ NEET UG 2017
हिन्दीA U tube with both ends open to the atmosphere is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a distance of \( 10\text{ mm} \) above the water level on the other side. Meanwhile the water rises by \( 65\text{ mm} \) from its original level (see diagram). The density of the oil is:
Correct answer · Option D
\( 928\text{ kg m}^{-3} \)
Explanation
Pressure equivalence gives \( \rho_{\text{oil}} g h_{\text{oil}} = \rho_{\text{water}} g h_{\text{water}} \). Height of water column above original level = \( 65 + 65 = 130\text{ mm} \). Height of oil column = \( 130 + 10 = 140\text{ mm} \). Thus \( \rho_{\text{oil}} \times 140 = 1000 \times 130 \implies \rho_{\text{oil}} = \frac{1300}{14} \approx 928.5\text{ kg/m}^3 \).
