Question

Take a bar magnet (available in your laboratory), a small glass test tube with a cork partially filled with water and fixed on the piece of such a material say wood (float) that this system can float on water. Let the test tube and the float be kept floating in a water bath or some plastic tray containing water available in the laboratory. Bring the pole of the bar magnet near the water filled glass tube. Note your observation. Repeat the experiment without water filled in the test tube. Record your observation and draw conclusions.

Answer 1

With water in the tube, the floating setup is weakly repelled and moves slightly away from the magnet. With the tube empty, the movement is much smaller or not noticeable. This indicates that water is weakly diamagnetic; the effect is small and the glass tube can also contribute slightly.