Lab 19 ->oscilloscope warm up, NPN transistor(depletion zones), The Low Pass Filter, Diode circuit explanation.

We used Ashua's Oscilloscope to learn Voltage current in their relationship with power output.

From this part, we had draw a NPN transistor.

Here, we build a amplifier through the schematics shown in class.:

In physics, the graph of V vs Frequency, we dont count in more than 5 because it reaches good enough efficiency.

For these pictures, the analog oscilloscope was hooked to the function generator to see if similar patterns were recreated in the oscilloscope.

Low Pass Filter

The Low Pass Filter

A circuit was constructed by .1 uF capacitor and 22K resistor. By a tone generator app, one can see the low pass filter can help generate the graph of V vs. Frequency and other important applications when changing the frequency becomes important.

A more pronouced version of low pass filter.

Diode circuit explanation.

Showing Light bulb light up and as the proportional relationship with lumens vs voltage input from 3 to 4.5 volts of electricity from input box.

This was showing the example of closing the depletion zone and jump of voltage from 0 to 1.2 volts and suddenly the led bulb lights up at 1.35 volts.

Lab 18 ->Function generator and speaker. Activities from lab book, Mystery box solution, Error analysis

Setup of the Variac, photon beam deflector apparatus. 

Presentation of how photon beam deflector works.

Function generator

Hooking function generator to speaker for various range of sound in frequency outputs. 

Presenting the fluctuations of sounds through vibration of coils with approximately 8 ohm inside the speaker vibrating at frequency indicated by function generator.

Activities from Lab book

 Mystery box

The middle one was tricky because it shows in function generator but not in multimeter.

Pic of square wave

Sine wave

First beginning to setup

30 hz similar to 3d scoop. 

60 hz similar to a 3d rotated ring.

Error analysis: the errors are not necessarily solvable with variables given because all the apparatus required people to operate and every error is inside each apparatus's specification, thus there were no propagation of errors in operating but there is propagation of error in finding hz and divisions of amplitude of wave forms. From operational point of view, the error can come from apparatus, because there are noise of surrounding. And that noise transformed to the fluctuation as if quantum uncertainty of the waveform distributions as shown in apparatus. Ultimately, the error is derived purely by the environment disturbance and thus we had to be provided with better connector oscilloscope cables to minimize error in this experiment.

Lab 17 RC circuit capacitors -> Capacitors in both Series and Parallel, Charge Buildup and Discharge in Capacitor, dual capacitor dilemna and error analysis, RC system data deriving equations, UNDERSTANDING OF UNITS<=

Capacitors in both Series and Parallel

 From this lab, we were given two capacitors that were 1 uF each. The value actual value for each capacitor was found and recorded to be 0.965 μF and 0.978 μF. The capacitors were then put into a parallel circuit (as seen in the photo to the left. The capacitance was measured to be 1.979 μF. Then, capacitors were set up in series(as seen in the picture above) and the capacitance was measured to be 0.487 μF. From these values we can find a relationship between capacitors in series and in parallel. The relationship of total capacitance of capacitors in series is 1/Ctotal=1/C1+1/C2. In series, the charge is the same for the capacitors and so when looking at V=Q/C, the charge can be ignored and the only variable left is 1C. The relationship in parallel is Ctotal=C1+C2. In a parallel circuit, the voltage is the same for the capacitors and so when looking at the equation Q=CV, voltage can then be ignored and one can say C and V are proportionally related. From chart below, one can easily see how each of V, I, R variables can be calculated.

Solving the lab questions

Lab activities

General setup for Capacitor that charges rapidly and discharges rapidly

For this lab, a capacitor was charged up to show how energy is used up from it. As seen in the video below, first the light bulb is charged by the voltage. As the light dims and eventually goes out, that voltage charges up the capacitor. The two wires connected to the voltage box are then removed and put together (to close the circuit) and the light bulb turns on and once again, dims and eventually turns off. When the wires are removed from the voltage box and the circuit is closed, now the bulb is being powered by the capacitor. This lab showed how the capacitor works, its charged up and stores that power and then it is used up by other things such as the light bulb.

Charge Buildup and Discharge in Capacitor
Setup processes charging capacitor with dc source.

The capacitor was charged up to show how energy is used up from it. As seen in the video down below, light bulb is first charged by the voltage and as the light dims and goes out in around 5 seconds(not shown in video), that voltage is then charging up the capacitor. The two wires connected to the voltage box are then removed and put together (closing the circuit)  then, light bulb turns on and once again, dims and turns off slowly. When the wires are removed from the voltage source box, the circuit is closed, now the bulb is being powered by the capacitor. This lab showed how capacitor works; when it is charged up and stores energy and then used it up by resistor type of applications such as the light bulb. 

In order for the charges to be equilibrium, one had to calculate their relationship with each other. Because these capacitors are in parallel, the capacitance adds up and new capacitance of 0.94. The voltage can be calculated by Q/C and resulting 3.69 volts.

Percent error is -> (3.75-3.69)/3.69*100%=1.62% 3.75 is the experimental value from two parallel capacitor schematics. Mathematically, discharging capacitor takes infinite amount of time but 5 seconds for engineers. Time constant tao represent time system for significance of charge




RC system data deriving equations

Quantitative analysis was used for studying the RC system. The goal was to derive equation that describes the mathematics relationship between voltages across capacitor and time which describes the delta voltage as the capacitor discharges.

In the beginning, the voltage across the charged capacitor was measured. Also, the circuit, a current meter, LoggerPro and a resistor were all attached to the closed circuit. Data was gathered and a Potential vs. Time graph and a Current vs. Time graph was made. As seen in the LoggerPro graphs below, there are a total of four graphs; potential and current graphs for with voltage and potential and current graphs for without voltage. A best fit line was made for each of the graphs with the equation Ae-ct + B. The analysis of the formula can be seen in the unit analysis photo below. It can be concluded that the relationship between potential/voltage and time for a charged capacitor is VC=Vmax (1-e-t/RC) and for a discharged capacitor it is VD=Vmax e^(-t/RC). By showing the linear fit through the equations experimentally received, there is high correlation which means observed decay curve fit theory with equation of Q(t)=Qmax(1-e^(-t/tao)).

Potential and current vs time graphs

2nd Potential and Current vs Time Graph with higher correlation values.

Lab 16 ->Dissection of Capacitor, Measuring Permeability of Paper of Physics book, Blowing up the capacitor

Dissection of Capacitor

Taking apart a capacitor.

Rolling out the capacitor film structure that stores charge. 

Types of capacitors ranging different prices.

Measuring Permeability of Paper of Physics book

Used sheets of paper from book as distance for charge measuring permissiveness.

Blowing up the capacitor

Demo of blowing capacitors out

Overall, toxic fume and tiny pop was enjoyed by all the surrounding people.
Basically the A is the overlap of circular cylinders of conductive wet material of capacitors.

Lab 15 -> Various Circuits and short error analysis, Configurations of 2 bulbs 2 batteris for the brightest shine*, Capacitor resistance with uncertainty,

Useful Equations simply shown

2nd useful equations

 Various circuit schematics

#1

#1 Video

Explaination of why middle one not lit

 Various Circuits

Demo of different circuit schematics.

#1 Two bulbs light and the third no light. Predicted switch closed and bulbs having different brightness due to parallel and series lightness which series connected light bulbs would light up brighter than the parallel connected light bulb.

However, the result was the third in the middle stayed unlit and b/c the potential difference between the junctions were zero.  Up and down cancels as shown above.

#2 Vid

#2 Video new removal one bulb around same brightness

The error for this one is not distinct enough for the eye to detect and there is not enough light sensitive apparatus to make sure the intensity of light is constant b/c the geometry of the circuit could also be giving misleading results.

#2

 #2 , Both bulbs were lit and the switch was originally open. Prediction that the third light bulb would dim the 2 light bulbs even though an extra battery is added b/c the junction is zero in the new circuit added if pole were to be closed.

However, the result is nothing happened b/c the potential being the same from the left and right side and they are still being powered by the same batteries b/c the new battery is added a wrong way that makes junction point zero.

Error for this one is when closing the 2nd pole, the two seemed dimmed a tiny bit which could be the geometry of the set up not perfectly reflecting the diagram as the two junction point from the new circuit should not be effecting the two bulb.

Configurations of 2 bulbs 2 batteris for the brightest shine*

Result: Series and parallel of bat. bulb gives brightest configuration.

Testing circuitry with multimeter

one of medium configuration with "perfect wires". (same brightness)

4 configuration with more through testing with "perfect wire"

Resistor clipped in half.

Measuring resistance

Resistor in parallel.

Useful Equations

Solved the Resistor's resistance along with uncertainty.

The uncertainty is then compared to the manufacturer's standard which the range of experimental value matches with manufacturer standard of +/- 10%.