Lesson 2
Getting Down To Basics
Objectives:
When the students have finished this chapter they should be able to
answer questions on the basic concepts of:
- elementary atomic theory
- conductors
- insulators
- resistance
- direct current
- alternating current
- electromotive force
- magnets
- cells and batteries
- schematic diagrams
Apparatus:
- primary and secondary cells
- clip leads
- resistors of various types
(old circuit boards with resistors
are useful)
- samples of conductors and non-conductors
- measuring and monitoring equipment
- oscilloscope
- VOM
- analogue voltmeter
- horseshoe and bar magnets and iron filings
(you probably
could borrow these from the Science Department of your local high
school)
Handouts:
Lesson Plan:
- Answer any questions about the homework, especially those dealing
with math skills
- Use a VOM to demonstrate conductivity and how to identify
conductors versus insulators. Encourage your students to invest in an
inexpensive VOM.
- Use a VOM to show how to measure resistance. Have students
determine resistance of resistors.
- Have students determine the resistance and tolerance of resistors
from the colour codes. You may have to review using
percentages.
- The lines of magnetic force can be demonstrated by putting a bar
magnet under a piece of paper and scattering iron filings on the paper
above the magnet.
- Demonstrate the use of the VOM to measure DC. Have the students
measure the voltages of various cells.
- Use cells and clip leads to demonstrate the voltage of cells
arranged in series and in parallel.
- Use a coil, horseshoe magnet and an ammeter to show that a flow of
current is generated when a coil is moved through a magnetic field, a
magnetic field is moved around a coil, and a combination of
both.
- Use an oscilloscope to show an AC waveform. This is an ideal
opportunity to introduce the terms frequency, wave length, and
amplitude. Show waves of different frequencies.
- Demonstrate the use of the VOM to measure AC.
Homework:
- Read the rest of Chapter 2.
- Do the Chapter 2 Quiz.
- Skim Chapter 3.
Chapter 2 Quiz
Printable copy of the Review Quiz
Answers to Chapter 2 Quiz.
1 |
B |
9 |
A |
17 |
D |
25 |
B |
33 |
A |
2 |
C |
10 |
B |
18 |
A |
26 |
C |
34 |
A |
3 |
D |
11 |
A |
19 |
B |
27 |
C |
35 |
A |
4 |
D |
12 |
C |
20 |
C |
28 |
B |
36 |
D |
5 |
A |
13 |
B |
21 |
A |
29 |
A |
37 |
A |
6 |
D |
14 |
D |
22 |
D |
30 |
D |
38 |
D |
7 |
B |
15 |
A |
23 |
D |
31 |
A |
39 |
B |
8 |
A |
16 |
A |
24 |
B |
32 |
D |
* |
* |
Overhead Slide Versions of the Diagrams
- Slide 1
2.1
Hydrogen Atom
2.2 Helium Atom
2.3 Copper Atom
- Slide 2
2.4
Current Flow in a Conductor
- Slide 3
2.6
The Resistor Colour Code
2.5 Colour Code Table
- Slide 4
2.9
Direct Current, Graph of current flow
2.10 Direct Current,
Graph of voltage
- Slide 5
2.11
Cells in Parallel, Physical Diagram
2.12 Cells forming a
Battery
2.13 Cell with a load, physical layout
2.14Cell with
a load, schematic diagram
- Slide 6
2.15
Battery Reversal, Voltage Graph
2.16 Battery Reversal, Current
Graph
2.17 Alternating Current, conceptual drawing
- Slide 7
2.18
AC half-cycle
2.19 One cycle of voltage sine wave showing
degrees
2.20 One cycle of Current sine wave showing degrees,
(in phase with 2.19)
2.21 Several sine wave cycles, with names
- Slide 8
2.22
Comparison of power in AC cycle and DC of same duration