Aim of the experiment is to Measure the Magnetic Susceptibility of FeCl3 solution by Quinke’s Method.
In this experiment we have used An electromagnet, its power supply, A Gauss Meter, along with a probe and Qunike’s Tube (or U-tube) with FeCl3 solutions. By the help of Gauss Probe one can measure the magnetic field intensity (H) in the unit of Gauss. (1 Tesla= 10^4 Gauss). What we have to do, first we have to calibrate the magnetic field by providing the current and as a result the magnetic field intensity. After the calibration, we have to start the experiment, the important point to perform the experiment is to measure the reading for small h i.e. height of the solution in case of rise and fall from the standard value , means the level in the absences of external magnetic field.
When you calibrate the magnetic field then insert the Qunike’s tube in between the magnetic poles properly. If the two arms are very close of the U- tube, it is possible that both can be affected by the magnetic field and as a result no remarkable changes in to the height of the liquid level. But suppose if there is enough separation between the arms then you put any of the arms in the uniform magnetic field, which as a result you will see the raises in level and on the other hand fall of the level.
Here in this experiment level falls as a result of applying the magnetic field from the equilibrium position (that position of the level, when there was no magnetic field). Now how much it raises or falls from the centeral position by applying the external magnetic field we have to note down respectively. For an example the magnetic field intensity at one amp of the current, then at 2 Amp, 3 Amp and so on and further as a result on the change in level. So, there are only three variable; one is the current, second is the magnetic field intensity and the third one is the change in heights of the solution level. We have to record that data for the calculation of susceptibility. After making the observation now the points are (a). Why the level of solution rise up or fall down in the presence of magnetic field and (b) second how to derive the formula to measure the susceptibility
For the (a) you can see second part of the video where I have consider force along the x-axis, the direction in which we see the change in level. Also, the Z-axis is direction of the magnetic field. The level rise up or fall down because of this force that arises in the presence of external magnetic field on the magnetic dipole. For the (b) part you see the idea of force on magnetic dipole which is balanced by the pressure exerted over the area A due to height difference 2h between the liquid surfaces in the two arms of the U-tube.
Now in this experiment we define and measure the susceptibility as a ratio of Intensity of magnetization of the material to the intensity of external magnetic field. Now here to understand the susceptibility we have to Understand the intensity of magnetization, What is this? It is discussed into the second part of the video.