Question No - sciencembm.weebly.com€¦ · Web view8.13.2 Know that the test for hydrogen is that it explodes when mixed with air and ignited. 8.13.3 Know that when metal reacts

Moza Bint Mohammed Preparatory Independent School for GirlsScience Department

الوطنية االختباراتالعلوم في بنجاح

GRADE 8INDEX

UNIT NO

UNIT NAME CS NO PAGE NO

HOLT SCIENCE AND TECHNOLOGY (LIFE SCIENCE)

8L.1 Gas exchange 8.7.1,8.7.2,8.7.3,8.7.4,8.7.5 620-622,624,612-613,740,

8L.2 Circulation 8.8.1,8.8.2,8.8.3,8.8.4 606-610,6148L.3 Micro- organisms &

Food8.11.1,8.11.2 253,282,285

HOLT SCIENCE AND TECHNOLOGY (PHYSICAL SCIENCE)

8M.1 Atoms and Molecules 8.12.1,8.12.2,8.12.3,8.12.4,8.12.5,8.12.6 90,91,94-97,318,392-397,336-342

8M.2 Metals 8.13.1,8.13.2,8.13.3,8.13.4,8.13.6,8.13.78E.1 The Solar System 8.15.1,8.15.2,8.15.3,8.15.4,8.15.6,8.15.7,8.15.8 432,434,520,662-

664,646-659,618-620,688,690-691,554-557

HOLT SCIENCE AND TECHNOLOGY (EARTH SCIENCE)

8P.1 Energy 8.16.1,8.16.2,8.16.3,8.16.4,8.16.5,8.16.6 240-242,247-257,264-267,298

8P.2 Electromagnetism 8.19.1,8.19.2,8.19.3,8.19.4,8.19.5,8.19.6 518-526

GRADE 8: Life science 1

Gas exchange8.7.1 Know the basic structure of the lungs and their role in gas exchange (breathing).

8.7.2 Know that inhaled air has more oxygen than exhaled air, and that exhaled air has more carbon dioxide than inhaled air.8.7.3 Know that oxygen and carbon dioxide are carried round the body to and from cells in blood vessels.

Name :……………………….. Class: ………….. Date : …………………..


8.7.4 Know that smoking damages the lungs and reduces the efficiency of gas exchange.8.7.5 Compare and contrast the similarities and differences between red and white blood cells and their functions.

Choose the correct answer

1 What substance is used as the main energy resource in our bodies? (CS 7.1)A proteinB glucoseC oxygenD water

2 How is oxygen transported around the body? (CS 7.5)A carried on red blood cellsB as a gasC carried on white blood cellsD attached to glucose

3 When you exercise: (CS 7.2)A your pulse rate stays the same, but your breathing rate goes up.B your pulse rate goes up, but your breathing rate goes down.C your pulse rate goes down, but your breathing rate goes up.D your pulse rate goes up, and your breathing rate goes up.

4 How is carbon dioxide transported around the body? (CS 7.3)A carried on red blood cellsB as a gasC carried on white blood cellsD dissolved in the plasma

5 Air entering the lungs would pass through the following structures in the order: (CS 7.1)A trachea bronchus air sac alveoliB trachea bronchus alveoli air sacC alveoli trachea bronchus air sacD bronchus trachea air sac alveoli

6 What part of the lung is labelled Y, in the diagram? (CS 7.1)A diaphragmB windpipeC air sacD bronchus

Constructive response Questions:

1.The alveoli are the parts of the lungs where gaseous exchange takes place.

A) Below are three features of the alveoli which help in gaseous exchange (CS 7.1).


Choose one feature and explain how it helps in gaseous exchange. thin walls good blood supply moist lining

_____________________________________________________________

B) Explain why damage to alveoli results in less gaseous exchange.

______________________________________________________________

2. Marium used the apparatus shown below to collect a sample of exhaled air.A) There are differences in composition between the air that Marium breathed in and the air that she breathed out. (CS 7.2)

Copy and complete these sentences, choosing the correct word from each pair. i Inhaled air contains _________oxygen than exhaled air.

ii Inhaled air contains _________ carbon dioxide than exhaled air.

B) Candle X will burn for longer than candle Y. Explain why.

________________________________________________________


3. A) Name the parts labelled X, Y and Z.(CS.7.1)

X __________________________

Y __________________________

Z __________________________

B) Gas exchange occurs in the alveoli of the lungs. What is meant by ‘gas exchange’?

_____________________________________________________________

_____________________________________________________________

C) Give two features of alveoli that make them suitable for gas exchange.

____________________________________________________________

____________________________________________________________

D) Give three differences between the air you breathe in and the air you breathe out.Breathed out air contains …

i _________________________________________________________

ii _________________________________________________________

iii ________________________________________________

4. Carbon monoxide, nicotine and tar get into the lungs when a person smokes.Draw a line from each substance to the effect of the substance on the body.Draw only three lines. (CS8.7.4)

Substance Effect of the substance


5.Compare and contrast the similarities and differences between red and white blood cells and their functions? (CS8.7.5)

…………………………………………………………………………………………………………………..

…………………………………………………………………………………………………………………..

………………………………………………………………………………………………………………….

Grade 8: Life science 2

Circulation8.8.1 Know the basic structure of the heart and relate this to its function.8.8.2 Know the different valves of the heart and how they function.8.8.3 Know the positions, functions and names of the major blood vessels.8.8.4 Recognise the differences between arteries, veins and capillaries, and relate their structure to their function.8.8.5 Explain blood pressure and why high blood pressure is an indicator of circulatory problems.

1) After leaving the left ventricle, blood enters directly into the ( CS 8.3)A. aortaB. vena cavaC. coronary arteryD. pulmonary artery

2) Blood enters the left atrium through the ( CS 8.3)A. vena cavaB. pulmonary veinsC. coronary arteriesD. pulmonary arteries

3) The average blood pressure in mm Hg of a healthy male while exercising is likely to be ( CS8.5)A. 80/120B. 120/80C. 90/140D. 140/90

4)The "lub" sound of the heart is caused by the closing of the ( CS8.2)A. AV valvesB. aortic valveC. pulmonary valve D. semilunar valves5) There is a difference in the thickness of the muscle in the walls of the right and left ventricles because of the high pressure that must be generated by the ( CS8.1)A. left ventricle to pump blood to the lungsB. right ventricle to pump blood to the lungsC. left ventricle to pump blood to the entire bodyD. right ventricle to pump blood to the entire body


6) Arteries are best defined by the ( CS8.4)

A. presence of one-way valvesB. oxygen content of their bloodC. quantity of CO2 dissolved in their bloodD. direction of blood flow in relation to the heart

7) Which sequence of blood flow is correct? ( CS8.3)

A. Left ventricle to the aortaB. Vena cava to the left atriumC. Pulmonary artery to the left atriumD. Right Ventricle to aorta

8) Because arteries have elastic muscular walls, they have the ability to ( CS8.4)

A. maintain blood pressureB. prevent the escape of bloodC. reduce friction against blood flowD. Prevent back flowof blood

9)Blood from the right Ventricle of the heart travels directly to the ( CS8.3)

A. body through the aortaB. body through the vena cavaC. lungs through the pulmonary veinsD. lungs through the pulmonary arteries

10)Blood in the pulmonary veins differs from the blood found in all other veins because it ( CS8.3)

A. is highly oxygenatedB. is under lower pressureC. does not flow into the heartD. has a higher concentration of sugar

11) What valve is between the left atrium and left ventricle ( CS8.2)

A. tricuspid B. mouth C. bicuspid D. semilunar valve

12) What makes the sound of your heartbeat A. heart valves closing B. your heart muscle pumping C heartburn D. vein valves closing


CONSTRUCTIVE RESPONSE QUESTIONS:Q.1)The diagram represents the flow of blood to and from a muscle. ( CS8.3.4)

A. What type of blood vessel is A that carries blood away from heart to the muscle? …………………………………………………………………………………………….

B. Vessel A carries oxygenated or deoxygenated blood?

…………………………………………………………………………………………….

C. What type of blood vessel is B that carries blood from muscle to the heart?

……………………………………………………………………………………………..

D. Vessel B carries oxygenated or deoxygenated blood?

……………………………………………………………………………………………..

E. What is the process taking place inside the capillary of the muscle?

؟ …………………………………………………………………………………………

Q2. Define the Following: (CS8.8.4)

1.cardiovascular system________________________________________________________________________________________________________________________________

2. artery________________________________________________________________________________________________________________________________

3. capillary________________________________________________________________

4. vein________________________________________________________________________________________________________________________________

5. pulmonary circulation________________________________________________________________________________________________________________________________

6. systemic circulation________________________________________________________________________________________________________________________________


Q3.

Which are the 4 major blood vessels of heart? Name them. (CS8.8.3)

…………………………………………………………………………………………………………….

…………………………………………………………………………………………………………….

1. Look at the picture answer the following questions :

a) The pulmonary artery takes blood from ______________ to the ___________

b) The pulmonary vein takes blood from the lungs to the _____________

c) The _______________ carries deoxygenated blood in the body to the right atrium.

d) The __________ carries oxygenated blood from the left ventricle to the body.

Grade 8: Life science 3Micro-Organism

8.11.1 Know that micro-organisms are used in making foods such as bread, cheese and yoghurt.

Q1 : Complete the table below by putting a tick in one or both columns:

Food Made using fungi Made using bacteria

YoghurtCheese

Soy sauceBreadWine


Vinegar

Q2: Put true ( √ ) or false ( × ) in the following sentences:

1) Cheese and yoghurt are made by mixing bacteria with milk ( ).

2) Bacteria are used in making bread and yoghurt ( ).

Materials 1Atoms and molecules

UNIT 8M.112.1Know that the smallest particle of an element is an atom and that atoms of one element are of one kind and are different from atoms of every other element.

12.2Know that elements join together chemically to form compounds, that the smallest particle of a compound is a molecule, and that all molecules of a compound are made up of the same fixed number of atoms of the constituent elements.

.12.3Know that all elements can be represented by a symbol, compounds by formulae and reactions by equations.

12.4Know that mass is conserved during a chemical reaction and that the number of atoms of each element taking part in the reaction remains unchanged.

12.5Recognise Mendeleev’s periodic table as a means of classifying elements according to their properties. Identify where the more reactive and the less reactive metals occur on the periodic table and where the metals and the non-metals occur.

12.6Know that elements with similar properties are arranged in columns in the periodic table and that the properties of elements change gradually along the rows.

.

CHOOSE THE CORRECT ANSWER:

1 An atom is: (CS12.1)A the smallest particle that can exist.B a group of particles that are all the same.C the smallest particle of a compound that exists under normal conditions.D the smallest particle of an element that exists under normal conditions.

2 A molecule is: (CS12.2)A the smallest particle that can exist.B the smallest particle of an element that can exist.C two or more atoms chemically joined together.D the same as an atom.

3 The substances that you get at the end of a chemical reaction are called: (CS12.3)A reactants.B chemicals.C products.D gases.

.4 Which of these things is an element? (CS12.1)

A saltB waterC oxygen


D air

5 An element is something that: (CS12.1)A can be split up by a chemical reaction.B cannot be split up by a chemical reaction.C is made up of different kinds of atom.D is a mixture of atoms and molecules.

6 The correct way to write the chemical symbol for calcium is (CS12.3)A CAB CaC caD Cal

7 Where are metallic elements found in the Periodic Table? (CS12.5)A on the right-hand sideB on the left-hand sideC in the top rows onlyD in the bottom rows only

8 The name of the compound that you get when magnesium burns in oxygen is: (CS12.3)A magnesium oxide.B sodium chloride.C magnesium chloride.D sulphuric acid.

9 Water is an example of: (CS12.2)A an element.B an atom.C a compound.D an alloy.

10 How many elements are there in the compound iron sulphide? (CS12.1)A oneB twoC threeD more than three

CONSTRUCTIVE RESPONSE QUESTIONS:

Q1) Air contains oxygen, nitrogen, argon, some water vapour, and a little carbon dioxide.

Complete each row in the following table by ticking one box and by stating the number of atoms in one molecule of the substance.

The first row has been done for you.

oxygen

carbon d ioxide

nitrogen

substance it is anelement

it is acompound

it is amixture

number of atomsin one molecule

2


Q2)

From the substances named above, give:

(i) the name of a metal;

.................................................................................................................

(ii) the name of an element which is a non-metal;

.................................................................................................................

(iii) the name of an element which will rust;

.................................................................................................................

(iv) the name of a compound.

.................................................................................................................

Q3) Air is a gas at room temperature. The chemical formulae below show some of the substances in the air

Ar CO2 H2O N2 Ne O2

(a) Put these formulae in the correct columns in table A to show which substances are elements and which are compounds.

table A

G old, iron and m agnesium are elem ents w h ichconduct e lectr ic ity.

S ulphur and phosphorus are elem ents w hichdo conduct e lectric ity.

W hen iron and su lphur a re hea ted toge ther,they react to fo rm a new substance ca lled ironsu lph ide.

not


(b) Put the formulae in the correct columns in table B to show whether the formula of each substance represents an atom or a molecule.

table B

Q4)Sharifa heated some copper powder until it turned black. When she allowed it to cool, it did not turn back into copper. She added the black substance to some dilute sulfuric acid. A blue solution was formed but a little of the black solid remained at the bottom. She separated the blue solution from the black powder and left it for some days in a shallow dish.

i. Is copper an element, a compound or a mixture? …………………………………………………………………………………………….

ii. Is the black substance formed when the copper was heated an element, a compound or a mixture? Give a reason for your answer.

…………………………………………………………………………………………………………

iii. Is the blue substance formed when acid was added an element, a compound or a

mixture? Give a reason for your answer.…………………………………………………………………………………………………

…………………………………………………………………………………………………

Q5) The diagram shows an outline of part of the Periodic Table of Elements. (CS 12.5)

elem ent compound

atom molecule


(a) What is the name of the element with the symbol H?

………………………………….

(b) In which regions of the Periodic Table are the following types of element found?

(i) non-metals (such as oxygen and chlorine);

region …………

(ii) very reactive metals (such as sodium and potassium);

region …………

(iii) less reactive metals (such as copper and zinc).

Region …………

(c) Why is copper sulphate not found in the Periodic Table?

……………………………………………………………………………………….

……………………………………………………………………………………….

Q6) The diagram below shows a model of a chemical reaction between two substances.

H

reg ion1

reg ion 2

region 3


(i) How can you tell from the diagram that a chemical reaction took place between substance P and substance Q?

......................................................................................................................

......................................................................................................................

(ii) Substance P is carbon.

Suggest what substances Q and R could be.

substance Q .................................................................................................

substance R .................................................................................................

(iii) How does the diagram show that mass has been conserved in this reaction?

......................................................................................................................

......................................................................................................................

GRADE 8: Materials 2Metals

8.13.1 Deduce a reactivity series for common metals based on their reactions with air, oxygen, water and dilute acids.8.13.2 Know that the test for hydrogen is that it explodes when mixed with air and ignited.8.13.3 Know that when metal reacts with air, oxygen or water, an oxide or hydroxide is formed and that if this is soluble in water, the solution is alkaline.8.13.4 Correctly place a metal in the reactivity series based on experimental evidence.8.13.6 Know that iron will rust in the presence of air and water, and that it can be protected from rusting by oiling, painting, galvanising, coating with plastic, electroplating and tin plating.8.13.7 Understand that reactive metals can displace less reactive ones from their compounds.

CHOOSE THE CORRECT ANSWER:


1. Which one of the following metal reacts vigorously with oxygen and water? (CS13.2,7)A. SodiumB. PotassiumC. CalciumD. Magnesium

2. Which gas are produced when metal react with acids (CS13.3)A. OxygenB. NitrogenC. HydrogenD Carbon dioxide

3. Which one of the following does not react with acids? (CS13.2)A. CuB. NiC. CrD. O

4. Which one of the following gas burns with the “pop” sound? (CS13.6)A. OxygenB HydrogenC. ChlorineD. Hydrogen sulphide

5. On burning metals react with oxygen to produce- (CS13.2)A. Metal hydroxideB. Metal chlorideC. Metal oxideD. Metal sulphate

CONSTRUCTIVE RESPONSE QUESTIONS:Q1) A scientist set up two test-tubes as shown below. ( CS13.7)


potassiumch loridesolu tion

z inc zinc

p latinumchlo rideso lu tion

A B

In test-tube B the zinc strip was slowly covered with a grey deposit.Nothing happened in the other test-tube.

(i) What was the grey deposit in test-tube B?

.................................................................................................................

(ii) Why was this grey deposit formed in test-tube B?

.................................................................................................................

(iii) Explain why no reaction took place in test-tube A.

.................................................................................................................

.................................................................................................................

(b) Look at each pair of chemicals in the table below.

Use the reactivity series to predict whether a displacement reaction would take place.Write yes or no in the second column and give the reason for your decision.

pairs of chemicalsDoes a displacementreaction take place?

yes or noreason

iron + sodium chloride ………….

……………………..

……………………..

magnesium + lead nitrate ……………… …………………


Q2) A group of pupils placed pieces of metal wire in different salt solutions. They recorded their observations in the table below.

(a) From these observations, write the order of reactivity of the four metals, copper, lead, silver and zinc.

most reactive ................................................

................................................

................................................

least reactive ................................................

(b) The pupils then dipped a new piece of each of the metal wires into dilute hydrochloric acid.

Only one of the metals reacted. Which metal was this?

....................................................................................................................

(c) One pupil predicted that there would be no reaction when he put a piece of zinc wire into a solution of silver nitrate.

Was his prediction correct? Explain your answer.

................................................................................................................................

Q3). (a) Magnesium chloride is formed when magnesium reacts with an acid. ( CS 13.1)


(i) Complete the word equation for the reaction between magnesium and this acid.

magnesium +…………........... chloridemagnesium

+ ............................

(ii) Suggest why magnesium chloride can be made by mixing magnesium with this acid but copper chloride cannot be made by mixing copper with this acid.

Ans : ……………………………………………………………………………………

(b) Copper sulphate is made by adding copper oxide to a different acid.Give the name of the acid which is used.

..........................................................................................

GRADE 8: Earth and space 1The Solar System

8.15.1 Explain night and day, eclipses, seasons, tides, and phases of the Moon in terms of the movement and relative sizes of the Sun, Earth and Moon. 8.15.2 Describe the relative positions of the planets, and their conditions compared with conditions on Earth.8.15.3 Be able to identify some planets in the night sky; know that we can see them and the Moon because they reflect light from the Sun. 8.15.4 Know that the Sun is a star and that, like all stars, it radiates light and heat. 8.15.6 Recount a number of uses for artificial satellites.8.15.7 Assess evidence for our modern understanding of the Solar System and show how this understanding has evolved over time. 8.15.8 Understand the importance of the Sun–Earth–Moon system in telling the time. Know the reasons for the differences between the Islamic calendar and the Gregorian calendar.

1. Which statement best describes our current ideas about the Solar System? ( CS 15.7)A. The planets all move in circular orbits around the Earth.B. The planets all move in circular orbits around the Sun.C. The planets all move in elliptical orbits around the Sun.D. The planets all move in elliptical orbits around the Earth.

2. The planets stay in their orbits around the Sun because of: ( CS 15.1)A the gravity pull from the Moon.B the gravity pull from the Sun.C magnetism.D the gravity pull from the Earth.

3. A satellite is: ( CS 15.6)A anything that orbits a planet.B anything that orbits the Sun.C something man-made that orbits the Earth.D a machine that sends TV programmes.

4. Artificial satellites can be used for: ( CS 15.6)


A sending telephone calls.B taking photos of the stars and other galaxies.C helping people to find where they are on the Earth.D all of the above.

5. The Moon: ( CS 15.1)

A. can always be seen during the day.B. orbits the Sun.C. is a small star.D. orbits the Earth.

6. We see a solar eclipse when: ( CS 15.1)

A. the Sun gets between the Earth and the Moon.B. the Moon gets between the Earth and the Sun.C. the Earth gets between the Sun and the Moon.D. the Sun stops producing light.

7. We have different seasons during the year because: ( CS 15.1)

A. the Earth’s axis is tilted.B. the Moon moves around the Earth.C. the Sun moves around the Earth.D. there are 12 months in the year.

8. The Sun feels warmer in summer because: ( CS 15.2)

A.. the Earth is closest to the Sun.B. the Earth is further away from the Sun.C. the Sun’s rays are more concentrated.D. the Sun’s rays are more spread out.

9. Stars are: ( CS 15.3)

A. lumps of hot rock in space.B. huge balls of burning gas, like the Sun.C. balls of burning gas, like the Moon.D. all very close to the Earth.

CONSTRUCTIVE RESPONSE QUESTION:

1) a The planet we live on is called ( CS 15.1) _____________________________________________.


b Is it daytime at place A or B? _______________________

2) a) The path a planet follows around the Sun is called its ( CS 15.1,2) __________________________ .

b) How long does it take for the Earth to go around the Sun once? Underline the closest answer:

24 hours 1 day 1 month 1 year

c) How long does it take for the Moon to go around the Earth once? Underline the closest answer:

24 hours 1 day 1 month 1 year

3) A lunar eclipse happens when the Moon is in the shadow of the Earth. ( CS 15.3)This diagram shows the Sun and the Earth.

.Draw the Moon in the place it would be during a lunar eclipse.

4) This diagram shows the Earth at two different positions in its orbit. ( CS 15.8)


a Write ‘summer’ and ‘winter’ under the correct parts of the diagram.

b Draw an X on the diagram to show where the Earth would be when it is spring in the UK.

c Give two differences between summer and winter in the UK.

....................................................................................................................................

...................................................................................................................................

5) Answer the following questions: (cs15.6)

a) What is an artificial satellite

……………………………………………………………………………………

…………………………………………………………………………………….

b) Write types of artificial satellite

……………………………………………………………………………………

……………………………………………………………………………………

…………………………………………………………………………………..

c) Write any three uses of satellite

……………………………………………………………………………………

……………………………………………………………………………………

……………………………………………………………………………………

GRADE 8: Physical processes 1

Energy

8.16.1 Classify common forms of energy as either kinetic or potential energy.8.16.2 Give examples of processes and devices that transform one form of energy into others.


8.16.3 Know that during energy transformations energy is converted from one form to others but that the total energy remains the same.8.16.4 Know that heat is produced in all energy transformations and that getting rid of waste heat energy is an engineering problem in many energy transformations.8.16.5 Know that the petrochemical complexes in Qatar use seawater to remove waste heat and know why there are strict regulations that control the temperature of the seawater that is returned to the sea.

8.16.6 Know and use the joule as the unit of energy

1)2)3)4)5)CONSTRUCTIVE RESPONSE QUESTIONS:

Q1) The statements below tell you what happens to the electrical energy used in some domestic appliances.• When a kettle boils, 94% of the energy is used to heat the water.• When a drill is used, 40% of the energy is wasted.• When a radio is used, 40% of the energy is given out as sound.

a. What proportion of the energy going to the drill is converted to energy in the rotating drill bit? What kind of energy is this? What happened to the ‘waste’ energy?

..................................................................................................................................................

b. Suggest what happened to the 6% of the energy supplied to the kettle that was not used to heat the water.

................................................................................................................................................

c. Which of the three appliances is the least efficient energy converter? Explain your answer.

………………………………………………………………………………………………………………

Q2).A football has gravitational potential energy of 10 J. It is dropped and bounces to four-fifths of the height from which it was dropped. What is its gravitational potential energy when:

A . it hits the ground? ...........................................

B. it reached the top of its bounce? ……………………………

Q3) This graph shows a ball rolling from A to G.


a) Which letter shows the ball when it has the maximum kinetic energy?....................

b) Which letter shows the ball when it has the maximum potential energy? …………….

c) Which letter shows the ball when it has the least potential energy?......................

d) Which letter shows the ball when it has the least kinetic energy?..........................

GRADE 8: Physical processes 2Electromagnetism

8.19.1 Know that a coil of wire carrying a current produces a magnetic field similar to a bar magnet; list the factors affecting the strength of an electromagnet.

8.19.2 Explain the function of the electromagnet in some everyday examples, such as in relays, electric bells and lifting devices.

8.19.3 Demonstrate that a wire carrying a current creates a magnetic field.8.19.4 Demonstrate and explain how a wire and a coil carrying a current move in a magnetic field.

8.19.5 Know how the movement of a current-carrying wire in a magnetic field can be exploited to make an electric motor; know how and why an electric motor turns and understand the function of the commutator.

On your answer sheet, write in or circle the correct letter for each question.

1) A magnetic field is:A a piece of ground with lots of iron in it.B the space around a magnet where it can attract magnetic materials.C the space around a magnet where it can attract all metals.D the space around a magnet where it repels magnetic materials.

2) Which diagram shows the shape of the magnetic field of a bar magnet?A B

C D

3) The direction of a magnetic field is from:A south to north.


B north to south.C west to east.D east to west.

4) Which statement about electromagnets is not true?A They can be switched on and off.B They are always magnetic.C They are made from coils of wire.D They need electricity to make them magnetic.

5) Which of these changes will make an electromagnet stronger?A Use more coils of wire.B Use a smaller current.C Use a wooden core.D Use fewer coils of wire.

6) This diagram shows part of the circuit for an electric bell.

When the switch is pressed, which statement is true?A The electromagnet will repel the armature.B The electromagnet will attract the armature.C There is no current flowing in the circuit.D The electromagnet will light up.

7) A relay is used in a car starter motor circuit so that:A the driver only touches the high current part of the circuit.B there are longer wires between the starter motor and the battery.C the car cannot be stolen.D the driver only touches the low current part of the circuit.

8) A magnetic field around a wire is caused by:A the plastic coating on the wire.B the coils of wire.C an iron core inside the wire.D an electric current flowing through the wire.

9) The shape of the magnetic field around an electromagnet is:A like the shape of the field around a bar magnet.B like the shape of a Christmas tree.C straight.


D square.

CONSTRUCTIVE RESPONSE QUESTIONS:

Q1) a) Give three ways you can make an electromagnet stronger.

i_______________________________________________________________

ii_______________________________________________________________

iiI______________________________________________________________

b) You can use plotting compasses to show the direction of the magnetic field around an electromagnet. Draw the needles in these compasses to show the direction they point when the current is on. One has been done for you.

Q2) Look at the picture and answer, why do you think that electromagnet better than a magnet for lifting iron at a steel works?

................................................................................................................................................

................................................................................................................................................

...............................................................................................................................................

Q3) Look at this electric bell and answer these questions:

a- Circle the electromagnet in this door bell


b- Sorting sentences into correct order from 1 to 6 which explains how the bell works.

□ Electromagnet attract the hammer

□ Spring wire is connected to the hammer

□ Switch on the electricity

□ Hammer will hit and hit the disc till the switch is turned off

□ Bell sound is heard

□ Hammer hits the disc

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Question No - sciencembm.weebly.com€¦ · Web view8.13.2 Know that the test for hydrogen is that it explodes when mixed with air and ignited. 8.13.3 Know that when metal reacts