Motion of an oscillating liquid column in a U-tube is

Which of the following examples represent (nearly) simple harmonic motion and which represent periodic but not simple harmonic motion? motion of an oscillating mercury column in a U-tube.

Write shorts notes on the oscillations of liquid column in U-tube.

A U-tube of uniform cross-section holds 1 kg of pure mercury and 0.2 kg of water in equilibrium. The diameter of cross-section is 1.2 cm. Relative density of mercury is 13.6. If the system in equilibrium is slightly disturbed, the period of oscillation of the liquid column in the tube will be (take g=10ms^(-2) )

What is the period of oscillation of a liquid contained in a U - tube executing shm ?

Explain the oscillation of a liquid in a U-tube. Find its time period.