Thursday, December 11, 2014

More AC Circuits


We began by working with an LRC circuit. This involved a capacitor, resistor, and inductor



Here we used several of our formulas to calculate values



For our lab we needed to find the resonance for our LRC circuit



Here are our calculations for the above lab. Anddddd that is the last lab, aaaBOOOYAHHH

Ac Circuits

Here we used our lab tools to record voltage and current for an AC power supply.



Above we graphed the data from the previously mentioned lab.



Here we measured the reactance of a capacitor



The last lab performed we connected a resistor and a capacitor in an AC circuit. We calculated the total resistance/impedence

Inductance


We began today by discussing the topic of inductance. We then represented it mathematically.



In our lab setup we used a resistor, function generator, and oscilloscope to calculate the inductance of an object

Here our are calculations for the above lab

Thursday, November 20, 2014

Magnetism part 2


Here we dealt with the issue of two current carrying wires and the forces between them. When they flow in the same direction they attract, the opposite and they repel





Here we measured the magnetic field with different amounts of coil. It increase with the amount of coils

Placing a magnet down two separate pipes, one metallic, it took longer for it to go down the metallic one. This is because the reaction force is to oppose the cause of it.

Magnetic Motors

Today we explored more on magnets, as well as how they can be used as motors

We first viewed the difference between a magnetic pin and nonmagnetic pin. The magnetic pin has all its small molecular poles pointing in one direction, which causes a net magnetic affect. We found that heating a magnet will destroy its magnetic property.



We then wrote an equation for torque on a current loop of t = u x B. u = IA. Above we solved a sample problem involving torque.



Here is a St. Louis motor, which is run off of a normal battery, which magnetizes the wires around the center loop. This interacts with the magnets on the side and creates motion



We attempted to make our own motor, but could not get it to work. Instead we took a video of another group who made a simpler motor work.



We also saw the magnetic field around a current carrying wire

Wednesday, November 5, 2014

Magnetism


Here we put a compass around a magnet to view the magnetic field around one
.

To see more clearly, we saw a picture of iron fillings sprinkled around a magnet.



Here we picked three surfaces, the big one around the whole magnet, one just to the left of the top, and one at the bottom. We found the net flux = 0, which proved the fact that a magnet can not have a single pole.


Professor Mason demonstrated the Lorentz Force with a magnet and an oscilloscope. When he approached the screen the parallel, nothing happened, but it did when it was perpendicular.



Here we sent current through a wire over a magnet. It repelled and attracted, depending on the current flow. This shows that current produces a magnetic field




Here we calculated the magnetic force of a bent wire. Instead of integrating, we just used excel.





















Electronics


Here we connected a phone, which was playing music, to an oscilloscope. It displayed its accompanying wave on the screen.



Here we lit up a LED light (pictured in red next to the black wire) on a breadboard connected to a power supply. The higher the voltage, the brighter the LED shined.






















We built a sound amplifier using the breadboard, the same power supply, as well as capacitors and resistors. We also used a transistor, which amplifies electronic signals. It is composed of a collector, base, and emitter. We also learned about a diode, which only allows current to flow through one direction through it.

Osciloscopes

We spent today by working with an oscilloscope, which is a device that displays voltage measurements via a beam on a screen




Here w did some calculations involving how the oscilloscope works.




























We connected a speaker to a function generator (pictured above on top of the oscilloscope) to produce different sounds. The function generator is capable of generating waves of different functions. We created different sounds by changing the function, as well as the frequency



Here we did some work with the oscilloscope and wrote down our observations




Next we attached an AC transformer, as well as kept the function generator connected. We then displayed several objects on the screen


LAB: Mystery Box

We were given a box and found the unknown voltage of each color.

Capacitors

Today we learned about Capacitors, which are devices that are used to store Voltage.
































Here we found that the capacitance (C) in a circuit for parallel and series is the opposite of a resistor. For series, 1/C total = the inverse of the individual resistances added. For parallel, Ctotal = the summation of all the capacitance.

















Here we charged a capacitor by hooking it into a circuit with a battery. Our calculation for the capacitor voltage was close to what we measured















We then saw the relationship of current and voltage of a capacitor in a circuit. As seen by the graph, as a capacitor charges, the voltage goes up, while the current goes down. The current eventually goes to zero because the voltage between the battery and the capacitor are now the same.

The last thing we did was build our own capacitor. We Found the value for k, which is the capacitance measured over what the capacitance would be if there was vacuum between the two plates, as opposed to material

DC Circuits



Here we began our lecture on Direct current to see how voltage and current work with resistors between parallel and series circuits. We predicted the light bulb in the middle would light up dimly if it was connected in the circuit, but we were wrong, it stayed out.




Above we connected bulbs in series. We found the current is the same throughout, however the voltage drops after each interaction with a resistor in the circuit.




Above we found in parallel circuits, the current is not the same as would be in a series circuit, however the voltage is the max offered by the EMF/battery.



Here we had to figure out the resistance of resistors based on the colors of them. We then tested them to verify their resistance, which was close to what they were marketed as.

Voltage of Continuous Bodies

Today we worked with finding Voltage involving continuous bodies. Principles of Gauss's Law were used in this section.


Here we wanted to find the Voltage around a ring. We used the integral shown, and also used excel to break it into 20 pieces and sum them up, which is shown below.



















Here we found the Voltage of a line with a charge density of lambda. The work above is similar to the method for Gauss's Law calculations


LAB: Voltage between, and around, two charges
We moved our Voltmeter around several places on the paper, with the two thumbtacks having a certain voltage, to measure the volts experienced at different places on the paper. The paper voltage changed at different places across the paper.