A Liquid Is Kept In A Cylindrical Vessel Which Is Being Rotated About Its Axis. The Liquid Rises At The Sides. If The Radius Of The Vessel Is 0.05 M And The Speed Of Rotation Is 2 Rev/s, Find The Difference In The Heights Of Liquid At The Centre Of The Vessel And At Its Sides.                                                                               

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A liquid is kept in a cylindrical vessel which is being rotated about its axis. The liquid rises at the sides. If the radius of the vessel is 0.05 m and the speed of rotation is 2 rev/s, find the difference in the heights of liquid at the centre of the vessel and at its sides.



Correct option is

2.0 cm


According to Bernoulli’s theorem, we have


At the sides the velocity is higher so the pressure is lower. Since the pressure on a given horizontal level must be same, the liquid rises at the sides to compensate for the drop in pressure. 






           = 0.628 m/s. 

           = 0.02 m. 

           = 2.0 cm.



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