Magnetic Field Sample Assignment

Conclusion

Magnet repels the copper pipe and didn’t get attached to it. As the field generated in the magnet and the copper pipe repels each other which in turn makes the magnet to slow down. Electromagnetic field induces due to the Faraday’s Law and Lenz’s Law and the behavior of the both law can be studied. Change in magnetic flux induces the EMF stated in the Faraday’s Law. Hence magnetic flux and Induced EMF are directly proportional to each other.

Homo-polar Motor

Procedure

A motor was built by using AA battery and small magnets. Adjust a connecting wire on the positive and negative terminal of battery so the rotor can move freely on the end of battery, a very simple rotor designed with the help of wire. Magnets provide us with the magnetic field. Positive terminal of the AA battery connected with the positive pole of magnet with the help of connecting wire. And negative terminal placed directly onto the negative pole or surface of the magnet.

Results

Experiment shows that there is a force named as Lorentz force which exists and tends to make the wire rotate freely on the battery in the direction of the rotor. The direction of rotor can be identified by the direction of the rotating wire as in which direction the force acting upon. The direction of rotor was counter-clockwise. The bent in wire can clearly explain the force acting on it which can be seen in the recorded image.

Conclusion

With the help of simple experiment, one can understand the phenomena of the Lorentz force and how it acts on the object when it comes in contact with the magnetic field. By setting and adjusting the polarity of magnet, direction of rotation can be obtained. The motor works in such way the current is travelling from the positive terminal towards the negative terminal which in turn causes the rotational movement also named as Lorentz force. By placing perpendicularly a conductor, such movement can be observed. Behavior and characteristics of Lorentz force were studied.

Simulations

All the experiments performed in this section, involved the simulation done by using the provided simulation software. Five of the different simulations were performed in this section and the last one, comprising.

Earth’s Magnetic Field

Procedure

Simulation files were obtained from the given link and simulation were performed under required settings in which Bar magnet tab was considered as necessary and all other process were unchecked. Needles of the compass directed towards the north and South Pole of the earth and hence the direction can be identified.

Results

Conclusion

North is basically a geographical term. It basically pointed towards the direction of the arctic pole of the earth. Thus it helps to find the arctic pole of the earth. And it has been observed that the magnetic pole lies towards the arctic pole in the north.

Flux Density

Procedure

By making small changes in the setting as using the field meter now instead of show planet box as not dealing the with the earth magnetic field now. Flux density and decay law correlated with each other and can be understood with the help of simulation tool. Four of the different readings were taken on the meter which represents the flux density x component and y component and the angle of flux density and its magnitude. Flux was measured at two different distances to observe the flux density decays law.

Results

From the results all the components of flux density can be calculated and can be used to calculate the index. From the log rule, following formula for magnetic field can be obtained to measure the index of the flux density decay law.

Conslusion

From the calculated results and values taken from the meter, it can be seen that the inverse square law is consistent and it gives the average index value near 2.13 and the expected outcome obtained from the results. Flux density keeps on decaying as it follows the decay law and hence verified and shows the behavior of decays law. At different angle different values were recorded and a clear decay in the flux density observed.

Coil Current and Coil Resistance

Procedure

Some of the changes had been made by using the same simulation files. Number of turns on coil can be adjusted in the electromagnet tab and current was set as the DC source. Coil properties can be observed by using the field meter. By making these settings, current through the coil and its resistance was measured. Experiment setting can be seen in the recorded image in the results section below.

Results

Positive and negative terminal of the battery connected with the help of wires with the coils placed in between them and the appropriate changes in the electromagnet tab of the settings have been made. A specified number of turns were placed on the coil and with the help of field meter current passing through the coil was calculated which in turns help to calculate the resistance of the coil by the Ohms law. The resistance obtained from this experiment was

Conclusion

From this experiment, it can be concluded that by setting the number of turns on the coil and assuming the single turn on coil has a radius of 1 cm, experiment can be performed. Conceptual understanding had been built. Simply by looking at the number of turns and the radius of the turns.

Induction

Procedure

This section was bit different from the previous ones, as now bar magnet, coil and a lamp was considered for further experiment. Again the simulation file was available on the provided link and obtained as guided and simulation was performed. The magnet was drawn near to the coil at different speed to observe the behavior of the bulb whether it illuminates and how rapidly and more precisely. As the magnet bar comes closer to the coil current flow through the coil and the bulb illuminates. That would identify at how much distance a magnet bar can work properly and how effective were the magnetic field. And by placing a transformer, an electromagnet attached with the coil and same experiment was performed again.

Results

This section shows the obvious setting of the experiment. Magnet bar was drawn closer and we can see the bulb illuminates as soon as it comes closer at the exact centre of the coil but at some distance within the radius of the coil bulb didn’t illuminate. And also if magnet lies stationary inside the coil. Different results had been obtained by moving the magnet bar. Lamp replaced by the meter to test the polarity changes in the voltage and current while moving the magnet bar. After that by clicking on the transformer tab, by choosing the electromagnet comes into the play and same test performed again.

Conclusion

It concluded that at stationary there was no illumination at lamp and movement in magnet bar increase or decreases the light of lamp as can be seen in the recorded images. With the help of meter in place of lamp, polarity changes can be observed which keeps on tapping when the magnet bar moves repeatedly. The experiment was to study the electromagnetic induction using a permanent magnet and the phenomena of transformers which clearly works on the self-induction. As the magnet was dragged in out, its magnet flux got disturbed in the same manner when fixed coil moves. And when held at the stationary, bulb didn’t illuminate as there was no changes in the magnetic flux. So here magnetic flux plays the role in the flow of current and induction of current.

Frequency Effect on Induction

Procedure

In last simulation performed in this experiment flux changes and the current induced by change in frequency can effect it, was examined. Frequency variation can be seen in this experiment and how it effects the intensity of light.

Results

Conclusion

It was observed that when the frequency was at its fullest, the voltage in the secondary winding was greater while it’s lower in case of the frequency at its half. The experimental setup can be seen in the result section which shows that a very few dim light in the lamp when frequency was at 50%. While it glows properly at the 100% of the frequency. Hence it proves that the frequency does make an impact on the current induction.

References

[1] Hoppe, Patrick. Wisconsin Technical College System. “Wisc-Online”. Ohm’s Law: The Relationship of Voltage, Resistance, and Current.
[http://www.wisc-online.com/Objects/ViewObject.aspx?ID=DCE8104]. (05/02/2013)

[2] Georgia State University, Department of Physics and Astrology. “DC Circuits”. DC Electric Power.
[http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elepow.html#c1]. (05/02/2013)

[3] Brightstorm. “Electromagnetism and Current”. Electromagnetic field theory.
[http://www.brightstorm.com/science/physics/electricity/rc-circuits/]. (18/01/2013)

[4] W. G. Olgham, University of California. “Induced EMF and Induction in Transformer”. Transformer studies.
[http://www-inst.eecs.berkeley.edu/~ee42/sp01/LectNotes/Lect8.PDF]. (05/02/2013)