A liquid is kept in a cylindrical vessel. When the vessel is rotated about its axis, the liquid rises at its sides. If the radius of the vessel is and the frequency of rotation is 2 revolutions per second, the difference in the heights of the liquid at the centre and at the sides of the vessel will be
2 cm
4 cm
1 cm
8 cm
Using Bernoulli's theorem, we have
Now .
Using this in (1), we get
Given, rev. per second, and .
Using these values, we get
,
which is choice (a).