Chapter 5: Electric circuits
Summing up
Science Quest 3: Glossary pages 254–61
Student: ........................................................................................................................................................ Class: . ...........................................................................
Complete the statements below to compile a summary of this unit. The missing words can be found
in the word list below.
1. All electric circuits consist of three essential items. They are:
power
supply
(a) a
to provide the electrical energy
load
(b) a
, in which electrical energy is converted into other forms of energy
conducting
(c) a
path which allows electric charge to flow around the circuit.
2. The electrical energy is transformed into other forms of energy only when the conducting path
complete . A
switch
of an electric circuit is
in the circuit allows you to
control whether or not electric current flows.
charge
3. Electric current is a measure of the amount of electric
passing a
particular point in an electric circuit every second. Electric current can be measured with an
ammeter
.
energy
4. Voltage is a measure of the amount of electrical
gained or lost by electric
charge as it moves through an electric circuit. The voltage across any two points in an electric
voltmeter
circuit can be measured with a
.
resistance
5. Electrical
is a measure of how difficult it is for electric charge to flow
through part of a circuit.
6. Conductors of electricity have very little resistance.
7. In metallic conductors, as long as the temperature remains fairly constant, a graph of
voltage drop versus electric current for the conductor yields a straight line. Its resistance is
constant
.
variable
8. A
resistor can be used to change the voltage across and electric current
flowing through parts of electric circuits.
series
9. When three light globes are connected to a power supply so that they are in
,
if one light globe ‘blows’, the others stop glowing. When, on the other hand, the same three light
parallel
globes are connected in
, if one globe ‘blows’ the others remain glowing.
short
10. A
circuit could make a battery go flat very quickly.
direct
11. The electric current supplied by a cell or battery is
current. The electric
alternating
current provided to your home by power stations is called
current.
breakers
12. Fuses or circuit
inside a meter box at home stop the flow of electric current
if it gets high enough to cause a fire risk.
quickly
13. Electrical power is a measure of how
electrical energy is transformed into
watts
other forms of energy. It can be measured in
.
diodes
14. Resistors, capacitors,
and transistors are examples of components that make
up electronic circuits.
15. The circuits etched onto the silicon chips inside electronic devices are called integrated
circuits.
resistance
direct
quickly
energy
complete
series
© John Wiley & Sons Australia, Ltd 2009
conducting
power
parallel
short
integrated
voltmeter
supply
load
charge
variable
constant
watts
switch
conductors
breakers
diodes
alternating
ammeter
Science Quest 3 Student Workbook
55