F2 IS First Term Pre-Examination Test 1

Kowloon Tong School (Secondary Section)

F. 2 Integrated Science

First Term Pre-Examination Test 1

Multiple Choice Questions

1.        A	2.          D	3.        C	4.        C	5.        D
6.        B	7.          C	8.        C	9.        B	10.      C

Fill in the Blanks

1.                           Noble gases                      

2.   (a)                      chemical                         

      (b)                          heat                             

      (c)                          light                             (Any order)

3.   (a)                 photosynthesis                    

      (b)                          light                            

4.   (a)                 carbon dioxide                    

      (b)               greenhouse effect                  

5.   (a)                     Breathing                        

      (b)               gaseous exchange                  

Short Question

(a)  Heat energy is released in burning. When the burning French fries is place below the  

      boiling tube, water in the boiling tube absorbs heat, causing the rise in temperature of  

      the water.                                                              

(b)  Jason should compare the increase in water temperature per gram of French fries     

      used. The greater the increase in water temperature per gram of snack used, the      

      higher the energy content of French fries.                                    

(c)  Jason should weight the piece of French fries before heating it on a Bunsen burner.    

(d) (i)    Extensive clearance of forest decreases the absorption of carbon dioxide in the   

              atmosphere.                                                        

      (ii)   Extensive burning of fuels increases the amount of carbon dioxide released to    

              the atmosphere.                                                      

      (iii)  These human activities increase amounts of carbon dioxide in the atmosphere.   

              This leads to an excessive greenhouse effect and hence global warming.         

      (iv)  There may be more cases of extreme weather conditions.                     

              The melting of ice in the polar region may speed up, leading to flooding in       

              low-lying areas. (or other reasonable answers)                               

F2 IS EXP 07 Answers

Experiment 8.3: Voltage and Electric Current (P.110-111)

Objective: To study the relationship of the number of dry cells, voltage of the dry cells and the electric in the circuit.

Procedures:

1.      Measure the voltage of one dry cell using a voltmeter as shown below on the left. Record the reading of the voltmeter.

2.      Disconnect the voltmeter. Set up the circuit shown on the right using the same dry cell as in step 1.

3.      Close the switch. Record the reading of the ammeter and the brightness of the bulb.

4.      Repeat steps 1 to 3 using two dry cells. Make sure the two dry cells are connected in the same direction.

5.      Repeat steps 1 to 3 using three dry cells.

Results:

Number of dry cells	Voltage (V)	Electric current (A)	Brightness of the bulb (arbitrary unit)*
0	0	0	-
1	0.5	0.15	+
2	1	0.25	++
3	1.5	0.3	+++

*Brightness of the bulb can be represented by the number of “+”

Plot a graph to show the relationship between the total voltage of the dry cells and the electric current of the circuit.

Discussion:

When more dry cells are connected in the same direction, the total voltage is higher.

The electric current flowing through the circuit is larger, so the bulb is brighter.

Conclusion:

The more the cell dry cells are connected in the same direction, the higher the voltage and

the larger the electric current flowing through the circuit.

F2 IS EXP 06 Answers

Discussion:

(a)    Explain the results in set-up A.

The mealworms take in oxygen from the air in the boiling tube and releases carbon dioxide.

Soda lime absorbs (吸收) carbon dioxide from the air in the boiling tube.

The total amount of the gas inside the boiling tube decreases (increases / decreases).

As a result, the red ink marker moves towards (towards / away from) the boiling tube.

(b)   What is the use of set-up B?

There is no mealworm in set-up B. If there is any change in the position of its red ink marker,

it means there are changes in other factors, e.g. temperature and air pressure. These factors

will also (not / also) affect set-up A.

By comparing the results in set-ups A and B, we can know the actual effect (真正影響) brought

about by the mealworms in set-up A. Set-up B is known as the control experiment for set-up A.

(a)    Explain the results in set-up C.

The mealworms takes in oxygen from the air in the boiling tube and releases carbon dioxide which is absorbed by soda lime.

The total amount of the gas inside the boiling tube decreases.

As a result, the red ink marker moves towards the boiling tube.

(b)   What is the use of set-up D?

There is no mealworm in set-up D. If there is any change in the position of its red ink marker, it means there are changes in other factors, e.g. temperature and air pressure. These factors

will also affect set-up C.

By comparing the results in set-ups C and D, we can know the actual effect brought about by the

mealworms in set-up C. Set-up D is known as the control experiment for set-up C.

Conclusion:

Ø   The mealworm takes in oxygen and releases carbon dioxide in both bright and dark conditions.

Ø   The gaseous exchange of the mealworm is the same in both bright and dark conditions.

F2 IS QZ 08 (8.1-8.3) ans

8.1 - 8.3

Fill in the Blanks (16 marks)

1      A dry cell(1) stores chemical energy and is a source of electrical(1) energy of a circuit.

2      A compete circuit which allows electricity to flow through is called a closed(1) circuit.

An open(1) circuit does not allow electricity to flow through.

3     Materials that allow electricity to pass through are called electrical conductors(1),

while those do not allow electricity to pass through are called electrical insulators(1)

4     Graphite(1) is a non-metal but it allows electricity to pass through.

5     A switch(1) can be used to open or close a circuit.

6     Electric current is the flow of free electrons(1) in a circuit. The direction of

flow is from the negative(1) pole to the positive(1) of the dry cell.

7     An ammeter(1) is an instrument used to measure the size of an electric current.

8     Electric current is measured in amperes(1). Small electric currents are measured in milliamperes (mA).

9     Voltage(1) of a dry cell is the “push” of free electrons to flow through the circuit. It is measured in volts(1) and can be measured by a voltmeter(1).

Circuit Symbol (6 marks)

Draw the circuit of the following electrical components.

Multiple Choice (7 marks)

Circle the letter of the best answer for each question.

1.       Ginny has the following set of electrical components. To build a circuit that can light up a bulb, which of the following components must be used?

(I)   A switch                                  (II)   A dry cell                                (III) Connecting wires

A. (I) and (II) only                B. (I) and (III) only                C. (II) and (III) only      D. All of the above

2.     Which of the following statements about these substances is true?

graphite

plastic

gold

iron

A.   All of them are electrical conductors.                     B.    All of them are electrical insulators.

C.   Only gold and iron are electrical conductors.         D.    Only plastic is an electrical insulator.

3.     Which of the following is a function of a switch?

A.   To break a circuit                                  B.    To supply electrical energy

C.   To control the brightness of a bulb         D.    To protect a bulb from an excessive electric current

4.     Which of the following instruments measures the size of an electric current?

A.   rheostat                   B.    resistor                     C.    voltmeter                 D.    ammeter

5.     The size of an electric current is measured in ___________ .

A.   volts                                B.    amperes                  C.    calories                    D.    joules

Challenging Questions (Bonus 3 marks)

Draw in the following diagram to show how to increase the voltage and current of the circuit. Draw wires to show how the circuit should be connected in order to measure the electric current flowing through the circuit. Indicate the positive (+) and negative (-) terminals of the ammeter.