NASA-Threads
Electricity and Magnetism
Lesson 29: Unit 1 Review
Lesson 29: Unit 1 Review
Unit 1, Quiz 1
Vocabulary
 Microcontroller – a small computer on a single integrated circuit that can be
programmed to read sensors, make decisions, and orchestrate devices that control
moving parts.
 Flowchart – graphical representation of a computer program.
 Schematic Diagram – graphical representation of an electronic circuit.
 LED – Light Emitting Diode
 Load – something that uses energy (in a circuit).
 Source – something that supplies energy (in a circuit).
 Charge – a measure of electrostatic force which can be either positive (+) or negative ().
 Circuit – a closed path that allows charge to flow.
 Electricity – the movement of charge (usually electrons).
 Conductor – material through which electrons travel easily. They contain a large
number of free electrons.
 Insulator – material through which electrons travel poorly or not at all.
 Semiconductor – material that can act like a conductor or an insulator depending on
certain conditions.
 Voltage (V) – an electromotive force (emf)/pressure that drives the flow of charge.
Work done in moving a charge from point A to point B in an electrical circuit, measured
in Joules (J), divided by the charge, measured in Coulombs (C):
1𝐽
1𝑉 =
1𝐶
1 𝑘𝑔∙𝑚2
 Joule - a unit of energy (SI system) equal to 𝑠2 .

Coulomb – a quantity of charge equal to 6.24 x 1018 electrons.
Programming/PBASIC Commands
 PBASIC – Parallax Beginners, All-purpose, Symbolic, Instruction Code.
 DEBUG – display information on the PC screen within the BASIC Stamp editor program.
o Syntax: DEBUG OutputData {OutputData}
 PAUSE – pause the program for a specified duration.
o Syntax: PAUSE Duration
 Variable – numeric or character data stored in memory. In PBASIC a variable can be
cleared as a Bit, Nibble (4 bits), Byte (8 bits), or a Word (16 bits). Variables must be
defined at the start of the program in a declaration statement.
o Syntax: varName var Byte
 HIGH (LOW) – make the specified pin output high (or low).
o Syntax: LOW Pin
 GOSUB – go to the specified subroutine and return after the subroutine has been
executed.
o Syntax: GOSUB Address
NASA-Threads




Electricity and Magnetism
Lesson 29: Unit 1 Review
IF…THEN – evaluate a specified condition and, if it is true, go to the point in the
program designated.
o Syntax: IF Condition THEN Address
DEBUGIN – retrieve information from the user via the DEBUG terminal window within
the BASIC Stamp editor program.
o Syntax: DEBUGIN InputData
DO…LOOP – create a repeating loop that executes the program lines between DO and
LOOP, optionally testing before or after the loop statements.
o Syntax: DO {WHILE | UNTIL condition(s)}
Statements(s)
LOOP {WHILE | UNTIL condition(s)}
OUTL/OUTH – output specified high or low signals to 8 pins (L – Low Byte: Pins 0-7, H –
High Byte: Pins 8 – 15).
o Syntax: OUTL = %10010101
Key Concepts/Computations
 Batteries are devices that convert stored chemical energy into useful electrical energy.
In a battery, the overall chemical reaction is divided into two physically and electrically
separated processes: one is an oxidation process at the battery negative electrode
where in the valence of at least one species becomes more positive, and the other is a
reduction process at the battery positive electrode where in the valence of at least one
species becomes more negative. When a battery is discharged, an electrochemical
oxidation reaction proceeds at the negative electrode and passes electrons into the
external circuit, and a simultaneous electrochemical reduction reaction proceeds at the
positive electrode and accepts electrons from the external circuit, thereby completing
the electrical circuit. The change from electronic current to ionic current occurs at the
electrode/electrolyte interface. (Source: http://batt.lbl.gov/batterybasics)
 The current carrying capacity of a conductor is a function of its inherent conductivity
(atomic structure/valence electrons) and its cross-sectional area.
 Individual electrons move relatively slowly in a conductor. However, a signal induced at
one end of a transmission line is carried by an electromagnetic wave, guided by the
transmission line, which travels near the speed of light (from approximately 0.6 to 0.9
of the speed of light, depending on the construction of the line). Source:
http://www.cyberhughes.com/PDFs/Smith_Chart/TLChar.pdf
Quiz Format/Content
 Write a program to blink an indicator (LED) 15 times, on 0.5 seconds, off 1.0 second and
then print “Shut Down” at the end of the program.
 Comment a section of code that includes DEBUGIN and subroutine(s). Program: Based
on keyboard input go to a specific subroutine and print something to the DEBUG screen.
 Brief Flow Chart: Fill in blank box(es) and/or answer questions about the program flow.
 Vocabulary:
o Compare and contrast a load and a source and give examples.
o Differentiate between conductors and insulators and give an example each.
 KVL – schematic with “black box” or numbers (determine load/source and voltage).
NASA-Threads
Electricity and Magnetism
Lesson 29: Unit 1 Review
Unit 1, Quiz 2
Vocabulary
 Current (i) – the quantity of electrons passing a given point in a given time. Measured in
Coulombs/second = Amperes (A).
 Resistance (r) – frictional losses that occur when electrons flow through a material. The
property of a material that describes how easily charge may pass through it. Measure in
Volts/Ampere = Ohms (Ω).
 Photoresistor – resistance varies with exposure to light.
 Potentiometer – variable resistor. Effectively creates 2 resistors with a center “tap”
(wiper), such that the 2 resistors always add up to the value of the potentiometer.
Key Concepts/Computations
 Measure current in a circuit (insert ammeter in the circuit). Current flow convention (+
to -).
 Current versus voltage in a lamp circuit is nonlinear because resistance of light bulb is
not constant.
 Quantity of electrons moving through a point in a circuit over a given time period.
𝐶
Example: 1.3A over 8 minutes: 1𝐴 = 1 𝑠
𝐶 6.24 ∙ 1018 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠
60𝑠
# 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠 = 1.3 ∙ [
]∙
∙ [8𝑚𝑖𝑛] = 3.89 ∙ 1021 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠
𝑠
𝐶
1 𝑚𝑖𝑛
 Ohm’s Law: V = IR. Linear relationship (R is the slope of the lien when plotting V versus
I).
 Resistor Color Codes: colored bands on resistors used to specify their resistance value
in Ohms.
 Series Resistance: resistors (loads) connected end-to-end in a circuit.
 Parallel Resistance: resistors (loads) connected across the same two nodes.
 Kirchoff’s Voltage Law (KVL): the total voltage around a closed loop must be zero.
 Kirchoff’s Current Law (KCL): the total charge (current) flowing into or out of a node
must be zero.
Quiz Format/Content
 Determine the value of a resistor given the resistor color codes (or given resistance,
state the color code). The resistor color code chart will be given.
 Compute Voltage, Current, and/or Resistance in a circuit given other two values (series
and parallel circuit).
Unit 1, Quiz 3
Vocabulary
 (Resistor) Tolerance – the amount (percentage) of possible variation from the specified
value.
Key Concepts/Computations
 Mean or Average – indicates the middle value or the expected value of a given data set.
NASA-Threads
Electricity and Magnetism
Lesson 29: Unit 1 Review
𝑛
𝑥1 + 𝑥2 + 𝑥3 + ⋯ + 𝑥𝑛 1
𝑥̅ =
= ∑ 𝑥𝑖
𝑛
𝑛

𝑖=1
Standard Deviation – a measure of the dispersion of the data in a data set. If the
standard deviation is low, then the points are dispersed near the mean…
𝑛
(𝑥1 − 𝑥̅ )2 + (𝑥2 − 𝑥̅ )2 + ⋯ + (𝑥𝑛 − 𝑥̅ )2
1
𝜎=√
= √ ∑(𝑥𝑖 − 𝑥̅ )2
𝑛
𝑛
𝑖=1



Histogram – relates the frequency of occurrences of data points to set intervals known
as bins. Identifies frequencies of occurrences in that data set.
Equivalent Resistance: Series – the sum of the resistor values in series.
Equivalent Resistance: Parallel – the inverse of the sum of inverses of the resistances.
1
1
𝑅𝑒𝑞 =
=
1
1
1
1
∑𝑛𝑖=1
+
+
⋯
+
𝑅1 𝑅2
𝑅𝑛
𝑅𝑖
Quiz Format/Content
 From a list of data points, compute the mean and standard deviation.
 Compute equivalent resistances from various schematic diagrams.
Unit 1, Quiz 4 (Exam 1)
Vocabulary
 Analog Signal (Continuous) – signals (e.g. voltage, current) which are continuous in
both time and value (magnitude).
 Digital Signal (Discrete) – signals which exist is specific (discrete) increments of time
and value (not continuous). Signals in digital electronics are typically “high” (1) or “low”
(0). (≈ 5VDC or 0 VDC in Transistor-Transistor-Logic (TTL) circuits)
 Quantization – limiting the set of all possible continuous values to a smaller set of
discrete values.
 Resolution – the number of bits used to represent quantized values (more bits means
higher resolution).
 Binary Number System – system of counting base 2 used in computers/digital
electronics. Each binary digit is called a “bit.”
 Analog-to-Digital Converter (ADC) – electronic component used to quantize a
continuous (analog) signal (voltage) into discrete (digital) values, which can be
processed by a digital circuit/computer.
Programming/PBASIC Commands
 PULSOUT – generate a pulse on Pin with a width of Duration.
Syntax: PULSOUT Pin, Duration
 SHIFTIN – shift data in from a synchronous serial device.
Syntax: SHIFTIN Dpin, Cpin, Mode, [Variable{\Bits}]
Key Concepts/Computations
NASA-Threads



Electricity and Magnetism
Lesson 29: Unit 1 Review
Servomotors/Navigation – Continuous Rotation Servos receive input signals (pulses) to
determine what speed and direction turn. On the Boe-Bot, the servos are controlled by
pulsing their signal lines with the PULSOUT command.
Velocity Profile/Ramping – on a plot of time (x-axis) versus velocity (y-axis), flat lines
indicate a constant velocity. Lines with a positive slope represent acceleration. Lines
with a negative slope represent deceleration.
Counting in Binary – counting in binary is done from right to left in base 2. The decimal
(base 10) values of each bit from right to left are 20, 21, 22,…2n. Therefore, adding a bit
doubles the size of the number that can be represented.
0 0000
8 1000
1 0001
9 1001
2 0010
10 1010
3 0011
11 1011
4 0100
12 1100
5 0101
13 1101
6 0110
14 1110
7 0111
15 1111
Serial Data Transmission – the process of sending one bit of data at a time (typically using a
synchronous clock pulse) over a single transmission line (in contrast with parallel data
transmission which sends multiple bits at