Transcript (1) 和(3)

A 是非題
細閱以下句子，正確的在空格內加上「」，不正確的加上「」。
1 電路必須有完整的迴路和電源，電流才會通過。 
2 所有非金屬都不導電。
×
3. 在有電源供應的閉合電路中，自由電子從電池的 ×

正極經電路淨流動到負極。

4. 電壓愈高，通過電路的電流愈大。
5. 可變電阻可用來調節電池的電壓。
×
B. 多項選擇題
試把代表正確答案的英文字母填在空格內。
1 以下電路中的燈泡沒有亮起來。
電池
這是因為
燈泡
A 電路中沒有電源。
B 電路沒有完整的迴路。
C 單一枚電池不足以使燈泡發亮。
D 把電池和燈泡連接的線不導電。
2
下列哪種物質是導電體？
(1)
海水
(2)
木
A 只有 (3)
B 只有 (3) 和 (4)
C 只有 (1)、(2) 和 (4)
D 只有 (1)、(3) 和 (4)
(3)
鋁
(4)
石墨
3 下列哪些關於開關的描述是正確的？
(1) 開關可用來使電路斷開或閉合。
(2) 開關由導電體和絕緣體構成。
(3) 不同種類的開關運作原理都不同。
A 只有 (1) 和 (2)
B 只有 (1) 和 (3)
C 只有 (2) 和 (3)
D (1)、(2) 和 (3)
4 下列哪項關於以下電路的描述是正確的？
A 如果在電路中加入更多電池，電阻器的電阻
便會下降。
B 如果在電路中加入更多電池，電池的電壓便
會下降。
C 如果電阻器的電阻增加，燈泡便會更光亮。
D 如果電阻器的電阻增加，電流便會減少。
電阻器
5 下列哪條導線的電阻最小？
物料
長度
直徑
A
銅
50 cm
1 mm
B
銅
30 cm
3 mm
C
鎳鉻合金
30 cm
3 mm
D
鎳鉻合金
50 cm
1 mm
C
問答題
1
完成下表
單位
電流
電壓
電阻
a 安培
d 伏特
g 歐姆
符號
b A
e V
h 
量度儀器
c 安培計
f 伏特計

2 參考下面的電路，回答以下問題。
滑動觸頭
裝置X
a 寫出裝置 X 的名稱。電阻器
電阻器
____________________________________
b 當裝置 X 的滑動觸頭從位置 A 移至位置 B
時， 燈泡和安培計分別有甚麼變化？
燈泡會變得更光亮。 安培計的讀數會增加。
____________________________________
c 如果電路中的兩枚電池以相反方向連接，燈泡會怎
樣？
燈泡不會發亮。
d 我們可以怎樣量度電路中電池組的電壓？
把伏特計連接到電池組的兩端。
伏特計的紅色端鈕連接到電池組的正極，
黑色端鈕則連接到電池組的負極。
e 舉出裝置 X 在日常生活的一項應用。
光暗調節器／音量控制器。
A
True or false questions
Write ‘T’ for a true statement and ‘F’ for a false statement in the boxes provided.
1 For a current to flow, the circuit must be a closed circuit and has a source of
electrical energy.
2 All non-metals do not conduct current.
T
F
3 In a closed circuit with an energy source, there is a net flow of free
electrons through the circuit from the positive terminal to the negative
terminal.
F
4 The higher the voltage, the larger the current flowing through the circuit.
T
5
A rheostat can be used to adjust the voltage across a battery.
F
B Multiple-choice questions
Choose the correct answer for each of the following questions.
1 The bulb in the set-up below does not light up.
This is because
cell
A there is no energy source.
B the circuit does not have a complete path.
C one cell is too weak to light up a bulb.
D the wire does not conduct current.
bulb
2
Which of the following is/are conductor(s)?
(1)
sea water
(2)
wood
A (3) only
C (1), (2) and (4) only
(3)
(4)
aluminium graphite
B (3) and (4) only
D (1), (3) and (4) only
3 Which of the following statements about switches are correct?
(1) They are used to open or close an electric circuit.
(2) They consist of both conductors and insulators.
(3) There are many types of switches. They work under different
principles.
A
(1) and (2) only
B (1) and (3) only
C
(2) and (3) only
D (1), (2) and (3)
4 Which of the following statements about the circuit below is correct?
resistor
A If more cells are added to the circuit, the resistance of
the resistor decreases.
B If more cells are added to the circuit, the voltage across
the cells decreases.
C If the resistance of the resistor increases, the bulb
becomes brighter.
D If the resistance of the resistor increases, the current
decreases
5 Which of the following wires has the lowest resistance?
Material
Length
Diameter
A
copper
50 cm
1 mm
B
copper
30 cm
3 mm
C
nichrome
30 cm
3 mm
D
nichrome
50 cm
1 mm
C Questions
1 Complete the table below.
Unit
Symbol
Measuring
instrument
Current
a ampere b
A
c ammeter
Voltage
d volt
e
V
f voltmeter
Resistance g ohm
h

2 Answer the questions with reference to the set-up below.
contact
device X
a Name device X.
Rheostat.
b When the contact of device X is slided from position A to
B, what happen to the bulb and the ammeter?
The bulb becomes brighter.
The reading of the ammeter increases.
c What happens to the bulb if the two cells are
connected in opposite directions?
The bulb does not light up.
d How can the voltage of the battery be
measured?
Connect a voltmeter across the battery.
Connect the red knob of the voltmeter to
the positive terminal of the battery and
the black knob to the negative terminal.
e Suggest ONE use of device X in daily life.
Used in dimmer switches / volume controllers.
Sentence structure
1. e.g. The higher the building, the higher the building
cost.
(a) The higher the manpower , the higher the
manpower cost .
(b) The higher the electricity
electricity cost .
, the higher the
(c) The higher the expenditure, the higher the
Expenditure cost.
2. e.g. A frying pan is used to cook food.
cable is used to transmit electricity ..
(a) A
_______
(b) A bucket is used to hold water
(c) A cart is used to carry loads
.
.
e.g. A classroom consists of desks and
chairs.
(a) A match consists of head and stem .
(b) A mushroom consists of stem and
domed cap
A food-chain consists of producers and
(c)____________________________________.
consumers.
.
4. e.g. If it rains, I will/shall bring an
umbrella.
(a) If _________, _________will/shall
________.
(b) If ________, ________will/shall
_________.
you come early, we will get many points easily
(c) If_____________________________.
a. If the students keep quiet, the lesson will be
finished earlier.
b. If the man drives carefully, the accident will not be
happen.
5. e.g. What happens to the passengers if the two
buses clashes?
(a) What happens to _________ if _____________?
(b) What happens to ________ if ______________?
What happens to the bulb if the switch on ?
(c) ____________________________________.
a. the students if the typhoon signal No.9 is hoisted
b. the car drivers if two cars crashed together
6. e.g. Peter is absent. It is because he is sick.
(a) _______________. It is because ___________.
(b) _____________. It is because _____________.
The old man is hungry. It is because he does not
(c) ______________________________________.
eat any food.
a. The students are happy. It is because they
win the game
b. The mother are angry. It is because her child is
naughtily