Sunday, May 18, 2014

Day 21:

Experiment #1 Measuring Earth Magnetic Field




The slope of this graph represents the magnetic field of  the earth. From the fit equation we determined that the earth magnetic field is 10.5 micro-Tesla.  The actual value is 25 to 65 micro-Tesla, and ourexperimental value is lower than the real value because of atmospheric considerations, such as the fact that we did our experiment inside a steel building.

Activity #2 Solenoid




We calculated the magnetic field of a solenoid, basically a very coiled conductor.


The calculated vs. the experimental value of the magnetic field is off by 0.04mT. 

Tuesday, May 13, 2014

Day 20:


Magnetic motors and magnetic fields




Experitment #1:




Attaching the power supply to the motor caused it to spin, and reversing the current's direction causes it to spin in the opposite direction.

Magnetic Motor:


The motor that our group created was composed of copper wire, several magnets and paperclips, and a power supply. A symmetrical oval shape was formed from the wire. One lead was sanded down 360 degrees while the other lead was sanded down half that amount. The paper clips were used as mounting points for the copper wire and placed on the top of the cup, and a magnet was placed inbetween the contraption as shown above. The current from the power supply is what moves the current through the wire and causes it to turn.


Sunday, May 11, 2014

Day 19:

Experiment #1 Field Directions





This demonstration illustrated the field waves around the "poles" of the magnet.

From this picture we found out that magnetic field lines come radiate, without intersecting, from one side of the pole into the other side of the pole.






We indicated the direction of the compass' point in several different locations around the magnet. From these lines, we found out that magnetic field lines go from the north pole into the south pole. So, a compass will point in the direction of the magnetic field lines.



Experiment #2 Magnetic Field, Force, and Velocity






In this demonstration, we used a rod, rails, and a power supply and predicted the directed the rod would roll.





Then we calculated the magnetic force.


Tuesday, May 6, 2014

Day18:


Activity #1: Amplifier





With this diagram as a blueprint to make an amplifier, we arranged our own capacitors and resistors and wires and connected them to an oscilloscope.



The resultant waves illustrates how the voltage is being amplified- the function on top is before amplification and the function on the bottom is after amplification. The bottom function has a noticeably larger amplitude.


Activity #2: AnotherAmplifier





This is an amplifier circuit arranged to amplify sound waves.





We used our phones to test the amplifier, which worked. The sound quality was actually quite good, but still imperfect.

Saturday, May 3, 2014

Day 17:


Oscilloscopes 


We used a function generator together with a speaker, an oscilloscope and a tap key to see how the various knobs and doohickeys affected the waves. We basically played around with it for a while and eventually got a feel for them


Sound From a Function Generator


We found that adjusting frequency altered the pitch of the sound produced by the wave. Amplitude controlled the volume or sound intensity. By selecting a different wave form, such as square wave, we found that the volume and pitch were both affected depending on our choice. The square wave was loudest.

The Vertical Voltage Axis


We turned the volts per division to 0.5 V and pressed the tap key. The line went up 3 divisions. The horizontal x-axis represented time and the y-axis represent voltage, so we multiply 3 x 0.5 (V/div) to get the battery's voltage, 1.5 V. It actually said 1.5 on the battery, too.

Lissajous Figures

Ratio 1:1 creates an ellipse figure

Ratio 2:1 creates an upside-down stretched infinity figure

Ratio 2:3 creates a fish shape

Ratio 2:1 creates an infinity figure


The pictures above are examples of Lissajous Figures. The shape of the figures are determined by the ratio of the two frequency received by the oscilloscope. The infinity symbol was my favorite. I instagrammed it with a caption that said "Physics Forever!" HA. Because infinity, get it?