SHUNG TAK CATHOLIC ENGLISH COLLEGE
Language Across the Curriculum
S.2 Integrated Science
ETV Worksheet 3 – Electricity at Home
Sources of Electricity and Electric Circuits
1. State two large household appliances are driven by electricity
2. What is the unit of voltage?
3. State the two main sources of electricity.
4. An ability of an electrical source to drive a current is known as v
.
5. What is the volt of a normal dry cell? __________
6. What is the volt of two connected dry cells? __________
7. The electricity current flows from the positive end of the source through the electrical
appliance to the negative end of the battery, the electric current flows in a fixed direction.
It is known as d
c
.
8. B
have limited energy supply, they are seldom used in large appliances;
we have to use the electricity come from the main supply by Power Company.
9. The voltage of the electricity from the main power station is much higher than batteries
up to __________ to __________.
10. The electric current from the main supply by Power Company is not a direct current; it is
an a
c
.
11. A closed alternating current is made up of three parts, which are the a
the source of electricity and the piece of connecting wire
S.2-IS-LAC-ETV Worksheet 2 Electricity and Circuits
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12. There is not distinction between the positive end and the negative end in an
a
c
. The voltage on one side r
u
,
but the voltage on the other side varies between ______V and _____V. When the voltage
on the right is higher, the electric current will flow from the
to the
.
When the voltage on the left is higher, the electric current will flow from the
to
the
.
13. Electric current flows back and forth in the circuit, but the changing direction of the
circuit occurs very quickly, reaching about _____ times per second.
Safe Installation of Electrical Appliances – Earth Wire and Fuse
14. The diagram below shows the structure of the common 3 pin plug and its colors.
I.
In a common 3-pin plug:
A.
B.
C.
II.
The pin in blue of the plug is inserted in the hole for the u
This is known as the n
pin.
The pin in brown is inserted in the hole for the c
v
this is known as the l
pin.
The pin in yellow and green on the top is connected to the e
voltage.
;
wire.
Why is the pin in yellow and green thicker and longer than other pins?
15. What is the function of fuse wire?
S.2-IS-LAC-ETV Worksheet 2 Electricity and Circuits
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Observe the Safety Guidelines for household Electrical Appliances
16. 5 ampere plug can be used in the appliances with the maximum of
volt.
17. 13 ampere plug can be used in the appliance with the maximum of
volt
18. 15 ampere plug can be used in the appliance with the maximum of
volt.
19. A plug should have marking showing the w
c
r
,v
s
with which the plug comply.
c
,
and the
r
20. If the statement is true, put a ‘’ in the provided box; if it is false, put a ‘’ in the
provided box.
I.
II.
III.
IV.
V.
VI.
Use 2-pin plug in any appliance.
Do not use broken and burned plugs.
It is much safer to use the 13 ampere plug with insulating sleeve.
Use water to put off the fire caused by electrical appliance.
Never attempt to touch the electrical appliance with wet hands.
When you see someone is caught by an electric shock, try to push
whom away by your hands.
S.2-IS-LAC-ETV Worksheet 2 Electricity and Circuits
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