ASJA BOYS’ COLLEGE CHARLIEVILLE

END OF TERM EXAMS – INTEGRATED SCIENCE

JUNE 2010

FORM 2

TIME – 2 HOURS.

INSTRUCTIONS TO CANDIDATES

1. This Paper consists of three sections – A, B and C.

2. Students are required to answer ALL questions in section A and B, and choose

any TWO questions in section C.

3. Solutions to section A will be done in the multiple choice sheet provided.

Solutions to sections B and C will be done in the spaces provided.

4. Calculators are not permitted in this examination.

5. If you finish before time, check over your work thoroughly.

Section A – multiple choice

1. All metals are good (a) Connectors (b) Conductors (c) Heavy (high-density) (d) light

2. We measure electric current in:(a) Volts (b) amperes (c) Ohms (d) degrees

3. Ohm’s law says that:(a) V = I / R (b) V = R / I (c) V = I x R (d) V = power

4. Use Ohm’s law to find the voltage when I = 5 amp and R = 10 ohms.(a) 15 V (b) 2 V (c) 50 V (d) 105 V

5. A unit of electricity costs 60 cents. The cost of running a 2 kW radio for 3 hours will be:(a) 120 cents (b) 180 cents (c) 360 cents (d) 63 cents

6. We measure power in:(a) Watts (b) amps (c) Ohms (d) joules.

7. All of these are electrical and thermal conductors except:(a) Copper (b) wood (c) Lead (d) silver

8. An insulator is defined as(a) A good conductor of electricity(b) An excellent alloy(c) A mixture of gases(d) A poor conductor of electricity.

9. All of the following are conductors except(a) Metals(b) Graphite(c) Electrolytes(d) Plastics

10. Electrical energy can be obtained from(a) Oil(b) Natural gas(c) Solar energy(d) All of the above.

11. A resistor is used to (a) Increase the flow of electricity in a

circuit(b) Decrease the flow of electricity in a

circuit(c) Make more electrons in a circuit(d) Remove electrons in a circuit.

12. An electromagnet is formed by(a) Passing a magnet over a piece of steel(b) Passing a current through a coil

around a nail(c) Passing a current in a metal slowly(d) None of the above.

13. When the same poles of two magnets meet the magnets will

(a) Attract each other(b) Repel each other(c) Bore each other(d) Destroy each other

14. Which of the following statements is true about magnets?

(a) A magnet can push electrons in an electric field

(b) A magnet can cause materials to be alive

(c) A flow of electrons through a conductor is called magnetism

(d) All metals show magnetism.

15. Which of the following is used to measure an electric current?

(a) Resistor (b) Voltmeter (c) Ammeter (d) Battery

16.The region in which attraction and repulsion extends in a magnet is called

(a) The electrostatic field(b) The magnetic field(c) The attraction field(d) The repulsion field

17. A metal that shows a high level magnetic force is (a) Magnesium(b) Copper(c) Iron(d) Sodium

18. A compass is used to show direction. The needle in a compass always points

(a) North(b) South(c) East(d) West.

19. Moving a magnet in and out of a coil makes a current that travels first one way, and then the other. This is called

(a) A direct current(b) An alternating current(c) A general current(d) A breaking down current

20. Direct current (d.c. current) travels in(a) One direction only(b) In both directions(c) Opposite directions at the same time(d) None of the above

21. Electricity can be made by (a) Moving a magnet near a coil of wire(b) Passing the magnet over a battery(c) Hammering a magnet into small pieces(d) Applying solar energy to the magnet.

22. The strength of a magnetic field in an electromagnet can be increased by

(a) Adding more coils(b) Increasing the current(c) Using thinner wires(d) All of the above

23. When magnets are heated until they become red hot they

(a) Become stronger magnets(b) Become weaker magnets(c) Lose their magnetic ability(d) Take part in a chemical reaction.

24. Appliances at home that contain electromagnets are

(a) Telephones(b) Bells(c) Televisions(d) All of the above

25. Which statement below is False about electrical energy?

(a) Electrical energy can be generated from solar energy

(b) Electrical energy is converted to sound energy in a television.

(c) All things require electrical energy to work(d) Electrical energy can be made using a

magnet.

Section BAnswer ALL questions in this section.

1. Complete the passage below using the following words.

Switched Attract Same Electromagnets Permanent Lines Magnetic field current Electric.

Poles that are different always ___(a) . Poles that the __ (b) always repel. Most materials are not good for making magnets. Steel is useful for making __(c) magnets.__ (d) __ are formed using coils of wire. Their magnetism can be __ (e) __ on and off. There is always a _ (f) __ field around a wire when it is carrying an ___(g)__ current. The bigger the __ (h) __ in the wire, the stronger the magnetic __ (i) __. A pattern of __ (j) _ shows the direction of the magnetic forces.

(a) (f)(b) (g)(c) (h)(d) (i)(e) (j) 10 marks

2. State whether the following are true or false.

(a) An electric current can be measured in amperes, using a voltmeter. _______(b) Lowering the resistance in a circuit will increase the current. _______(c) In a series circuit, when one bulb goes out the others remain lighting. _______(d) Rubbing electrons loose from their atoms makes static electricity. _______(e) There are two types of electrical charge – positive and neutral. _______(f) In order for a current to flow there must be a pusher and a pathway. _______(g) Adding extra lamps in a circuit in series will increase the resistance in the circuit. _______(h) Devices that use a large current use electrical energy very quickly. _______(i) A bulb lights when electrical energy is passed through a filament and a gas. _______(j) When one bulb in a parallel circuit goes out all the others go out also. _______

10 marks

3. Complete the table below.

Current (I) amps Resistance (R) in ohms Voltage (V) in volts

2 5 2 x 5 =4 310 412 1205 80

6 48

5 marks

4. Complete the following table.

Appliance Power rating in watts (W) and in kW (1000W)

Time used each day in hours

Energy used in kWh

Cost if 60 cents buys one unit kWh

TV 150 W = 0.15 kW 6 0.90 54 cents

Vacuum cleaner 750 W 2

Radio 4 W 10

Fridge 200 W 24

Heater 250 W 1

Electric stove 350 W 5

10 marks

5. The diagram below shows the magnetic field of a bar magnet.

(a) Name the parts labeled A, B and C.A: ____________ B: ____________ C: ____________ 3 marks

(b) Describe how you can:(i) Make a magnet

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2 marks(ii) Destroy a magnet’s magnetism

________________________________________________________________________________________________________________________________________________________

2 marks(iii) Make an electromagnet

________________________________________________________________________________________________________________________________________________________

2 marks

(c) Give a use of an electromagnet in the world today.__________________________________________________________________________________________________________________________________________________________________________

1 mark

10 marksSection C

Answer any two questions from this section.

1. (a) Define the terms conductors and insulators.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(b) Explain why electrical wires are covered in plastic or rubber.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(c) Draw a diagram to show a battery of two cells with three light bulbs connected in parallel. Include two switches: one switch must turn one of the bulbs on and off; the other must do the same for the other two bulbs.

(d) Suggest three ways in which electrical energy can be saved in your home._______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

15 marks

2. (a) State what the following terms mean.

i. Resistance______________________________________________________________________________________________________________________________________________________________

ii. Voltage______________________________________________________________________________________________________________________________________________________________

iii. Current______________________________________________________________________________________________________________________________________________________________

(b) Distinguish between a cell and a battery._________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(c) Explain what takes place when resistors are connected ini. Series

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

ii. Parallel____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(d) Name two things that can be done in a circuit to increase the overall resistance in the circuit.i. _______________________________________________________________________________

_______________________________________________________________________________ii. _______________________________________________________________________________

_______________________________________________________________________________

15 marks

3. The diagram below shows one end of the magnet being passed along the steel several times in the same direction without touching the steel with the magnet.

(a) Name the process taking place._____________________________________________________________________________________

(b) Explain what would happen if the bar was made of iron instead of steel.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(c) State what the term magnetic field refers to.__________________________________________________________________________________________________________________________________________________________________________

(d) Draw a fully labeled diagram to show an electromagnet.

(e) Name two things that can be done to increase the strength of an electromagnet.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

15 marks Total 100 marks

End of test

Have an enjoyable vacation.