Mechanical Properties of Fluids - Result Question 2
2. A 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 $10 mm$ above the water level on the other side. Meanwhile the water rises by $65 mm$ from its original level (see diagram). The density of the oil is
[2017]
(a) $425 kg m^{-3}$
(b) $800 kg m^{-3}$
(c) $928 kg m^{-3}$
(d) $650 kg m^{-3}$
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Answer:
Correct Answer: 2. (c)
Solution:
- (c) Here, $h _{\text{oil }} \times \rho _{\text{oil }} \times g=h _{\text{water }} \times \rho _{\text{water }} \times g$ $\rho_0 g \times 140 \times 10^{-3}=\rho_w g \times 130 \times 10^{-3}$
$\rho _{\text{oil }}=\frac{130}{140} \times 10^{3} \approx 928 kg / m^{3}$
$ [\because \rho_w=1 kgm^{-3}] $
