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GATE 2025 ME – Question 16

Fluid Mechanics · Bernoulli's equation and fluid acceleration · 1 mark · Multiple choice

Consider two identical tanks with a bottom hole of diameter $d$. One tank is filled with water and the other tank is filled with engine oil. The height of the fluid column $h$ is same in both the cases. The fluid exit velocity in the two tanks are $V_1$ and $V_2$. Neglecting all losses, which one of the following options is correct?

Two identical open tanks, one holding water and the other engine oil, with the same height $h$ and the same bottom hole of diameter $d$. The exit velocities are $V_1$ for water and $V_2$ for oil.
  1. $V_2 > V_1$
  2. $V_2 = V_1$
  3. $V_2 < V_1$
  4. Insufficient data to definitively conclude the relationship between $V_1$ and $V_2$

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Correct answer: (B) $V_2 = V_1$

Explanation

With no losses, Torricelli's law gives the exit speed $V = \sqrt{2gh}$, which does not depend on the density of the fluid. So $V_1 = V_2$.