1.Class Format

            Monday:

·        (Quiz due at 8:00)

·        Quiz discussions (8:00-8:15)

·        Introduction to the lab (8:15-8:30)

·        Lab (8:30-9:45)

·        Wrap-up (9:45)

Between Monday and Wednesday

·        Respond to blog comments

Wednesday

·        Lab (8:00-9:45)

·        Wrap-up (9:45)

Friday

·        Class starts at 9:00

·        Blog commenting (9:00-9:30)

·        Blog discussions (9:30-9:50)

Outside of class

·        Finish blog entries

·        Comment on 2 assigned blogs

·        Take home quizzes are due on Monday at 8:00 AM

2. Important Safety Rules

            Do

·        Switch off power whenever an experiment is being assembled or disassembled.

·        Discharge high voltage points to ground with well insulated jumper.

·        Remember capacitors can contain high voltage.

·        Make measurements in circuits with well insulated probes with a hand behind your back.

·        Avoid heat dissipating surfaces of high wattage resistors and loads because these can cause severe burns.

·        Take extra care when working with electrically hot (capable causing electric shocks) components.

·        Ask instructor to check out a constructed circuit before applying power.

Do NOT

·        Work alone on live electrical equipment.

·        Allow any part of your body to come in contact with any part of the circuit or equipment connected to the circuit.

·        Touch electrical equipment while standing on a metal or wet floor.

·        Use wet or ungrounded electrical equipment.

·        Wear watches or rings in the lab if it can be avoided: these can act as electrodes.

·        Lunge for a falling part of a live circuit like leads or measuring devices.

·        Touch two pieces of equipment simultaneously.

·        Touch any wire of a circuit; it may be capable of giving electric shock.

3. Current can easily kill or severely wound a person. Humans can sense current from as low as 1 mili Amp. Up to .01 Amps only a minor sensation can be felt but any higher and the hazards quickly escalate. Some effects include severe shocks, Muscular Paralysis and breathing difficulties only reaching up to .1 Amps. Anything between .1-.2 Amps leads to death. Past .2 leads to severe burns and muscle contractions that lead to a halt in breathing.

5. Tolerance is a small percentage that can be added or subtracted from the calculated resistor to make it closer to the average. For example, when calculating the resistance with ohms law each resistor had a gold band which implies the Tolerance is ±5 % of the actual value if needed.

                                              Results for Determining Values for Resistors based on Color

Resistors	Color	Color	Color	Tolerance	Total Calculated (Ω)	Actual Resistance (Ω)
Resistor 1	Blue: 6	Grey: 8	Brown: 1	Gold: ±5%	68*10^1=680	678
Resistor 2	Brown: 1	Grey: 8	Brown: 1	Gold: ±5%	18*10^1=180	177
Resistor 3	Red: 2	Violet: 7	Red: 2	Gold: ±5%	27*10^2=2700	2704
Resistor 4	Red: 2	Black: 0	Red: 2	Gold: ±5%	20*10^2=2000	2014
Resistor 5	Red: 2	Black: 0	Brown: 1	White: ±0%	20*10^1=200	200
Resistor 6	Red: 2	Red: 2	Red: 2	Gold: ±5%	22*10^2=2200	2259
Resistor 7	Orange: 3	White: 9	Brown: 1	White: ±0%	39*10^1=390	388
Resistor 8	Red: 2	Violet: 7	Brown: 1	Silver: ±10%	27*10^1=270	269
Resistor 9	Brown: 1	Green: 5	Red: 2	Gold: ±5%	15*10^2=1500	1490
Resistor 10	Brown: 1	Green: 5	Brown: 1	White: ±0%	15*10^1=150	152.1

The Tolerance for most of the resistors were ±5% of the calculated value which depended on the calculated resistance. All of the measured resistances were exceptionally close to the calculated values, being under the ±5% error mark.

Acutal Resistance (Ω)	Tolerance	Tolerance Value (Ω)	Calculated (Ω	Difference (Ω)
678	±5%	±34	680	8
177	±5%	±9	180	3
2704	±5%	±135	2700	4
2014	±5%	±100	2000	14
200	±0%	±0	200	0
2259	±5%	±110	2200	59
388	±0%	±0	390	2
269	±10%	±27	270	1
1490	±5%	±75	1500	10
152.1	±0%	±0	150	2.1

7. What is the difference between measuring the voltage and current using a DMM? Why?

Voltage is measured across a resistor using one probe on either side to show a voltage drop. Current, however, should not be measured across a resistor because the current would divide if the multimeter were connected in parallel. So, a multimeter should be connected in series with the resistor to measure the current in the circuit. Additionally, multimeter probes should be connected to the hole labeled for the purpose of measuring voltage or current, and naturally the multimeter should be set to measure this value as well.

8. How many different voltage values can you get from the power supply? Can each one of them be changed to any value?

A power supply has a 5 volt terminal, but it also has terminals for which the voltage can be selected. At these terminals the voltage can be chosen to be any value between 0 and 20 volts, though  it is most reasonable to select a value that is marked on the voltage source; ie any value in increments of 0.5 volts.

9. Practice circuit

• Measuring Current

• Measuring Voltage

Above is a close look at the use of probes
to measure voltage over a resistor.

                                        Proving Ohm's Law is Accurate for calculating Resistor values

Actual    Voltage	Calculated  Voltage	Calculated Current	Calculated Resistance	Actual Resistance	Tolerance	Accuracy
2 V	2.113 V	24.35 mA	86.6 Ω	82 Ω	± 5%	95%
3 V	3.27 V	36.9 mA	87.9 Ω	82 Ω	± 5%	93%
4 V	4.17 V	48.5 mA	85.9 Ω	82 Ω	± 5%	96%
5 V	5.02 V	58 mA	88.6 Ω	82 Ω	± 5%	93%
6 V	6.08 V	69.2 mA	86.8 Ω	82 Ω	± 5%	95%
2 V	1.96 V	2.14 mA	916 Ω	1000 Ω	± 5%	92%
3 V	3.296 V	3.28 mA	1005 Ω	1000 Ω	± 5%	99.50%
4 V	4.08 V	4.09 mA	997.6 Ω	1000 Ω	± 5%	99.80%
5 V	5.32 V	5.34 mA	996.3 Ω	1000 Ω	± 5%	99.60%
6 V	6.3 V	6.31 mA	998.4 Ω	1000 Ω	± 5%	99.80%

12. Rube Goldberg Circuit Diagram

Incorporating the Circuit into Rube Goldberg

A cart could block the sensor until another moving object moves it and allows light to reach the sensor, causing the motor to spin. the spinning motor would then wind up a string which would be connected to the next part of the Rube Goldberg machine. This string could be connected to many different things such as a pulley system that could lift a block from a pressure sensor, or a cart that could be affecting any sensor, or even a switch that would continue the process of the chain reaction.