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.
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.
9
9
Good job.
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