Friday, January 15, 2016

Lab 1


Week 1



Monday:

1.       What is the class format?  Each week will start with a pre-quiz, then a lab intro followed by working on the lab through Wednesday.  Friday includes blog discussions and the post-lab quiz.

2.       What are the important safety rules?  Never work with wet hands.  Power must be switched off when an experiment is being handled.  Do not work along with energized electrical equipment.  Know where the fire extinguisher, med kit, and phone are in case of emergencies. 

3.       Does current kill? Yes, about .2 amps can kill.

4.       How do you read color codes? (Video)
        You read color codes left right.  For example if you have black, red, orange, red, then gold you have 0, 2, 3, x100 ohms, and 5% tolerance.  That means you have 2300 ohms resistance with a 5% plus or minus tolerance.


5.       What is the tolerance? Give an example from your experiment.  Tolerance is the expected level of range in measured values of a resistor.

6.       Prove all your resistors are within the tolerance range.

       
Resister Band Value (Ω) Range (Ω) Tolerance Measured Value (Ω)
150k 142.5k - 157.5k 5% 147.6k
27.2 24.48 - 29.92 10% 2.71k
360 342 - 378 5% 358
120 114 - 126 5% 119
1.5k 1.425k - 1.575k 5% 1.48k
98.1k 88.29k - 107.91k 10% .816k
42 39.9 - 44.1 5% 46.3
2200k 2.09M - 2.31M 5% 2.258M
25k 23.75k - 26.25k 5% 14.94k
820k 779k - 861k 5% 816k






Wednesday:

1.       What is the difference between measuring the voltage and current using a DMM? Why?  You connect the positive probe to the upper right for voltage and resistance.  For amperage you connect the positive probe to the left of the ground.  When you measure voltage you connect to measuring alligator clips on both sides of the resistor, but when you are measuring the current you need to break the circuit to make the multi-meter part of the circuit.

2.       How many different voltage values can you get from the power supply? Can each one of them be changed to any value?  You can get any value for voltage from 0 to 25 on A and B on the power supply.  On the unchangeable connection the voltage is at a constant 5V all the time, it cannot be changed. 

3.       Practice circuit results (video) & (photo)




How do you experimentally prove Ohm’s Law? 
You experimentally prove Ohm’s law by taking a resistor of known value, providing a voltage of known value, and measuring the current to see if it falls within the predicted range depending on the tolerance of the resistor.  Provide measurement results. 
Register Band Value (Ω) Range (Ω) Tolerance Measured Voltage (V) Measured Current (mA) Calculated Resistance (Ω)
360 342 - 378 5% 1.05 2.84 369.718
360 342 - 378 5% 2.07 5.57 371.634
360 342 - 378 5% 2.53 6.81 371.512
360 342 - 378 5% 3.4 9.19 369.967
360 342 - 378 5% 4.05 10.93 370.54
100.2 95.19 - 105.21 5% 5 43.28 115.527
100.2 95.19 - 105.21 5% 4 34.38 116.347
100.2 95.19 - 105.21 5% 6.02 52.52 114.623
100.2 95.19 - 105.21 5% 8.35 72.8 114.698
100.2 95.19 - 105.21 5% 12.65 124.58 101.541




4.        Compare calculated and measured voltage, current, and resistance values. (Experimental   setup photo)


5.       Rube Goldberg circuit (video).




Friday:

Draw the circuit diagram for the Rube Goldberg set-up.




How can you implement this setup into a Rube Goldberg machine? Drawing required.
If you have some solar panels to charge a battery, a light sensor could be used to open the garage door if/when there is a power outage in your area. 













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