FIZIKMOZAC 2010

ELECTRICITY:TRIAL EXAM QUESTIONS

7.1 CURRENT & ELECTRIC FIELDS

1. Melaka Mid year 09: Question 8Diagram 8.1 shows an apparatus set upto observe a pattern of electric field.

(a) (i) What is meant by electric field?

.....................................................[1 mark]

(ii) In the space below, drawelectric field pattern formed bythe apparatus arangement onDiagram 8.1.

[2 marks]

(b) A current of 0.2 A is let to flow for3 minutes.Calculate(i) Quantity of charge carried

by the current[2 marks]

(ii) Number of electrons flow in3 minutes.

[1 mark]

(c) Q, R and S are three set ofapparatus to observe electricfield.

Set ofapparatus

Type ofpowersupply

Type ofelectrode

Typeof

liquidQ Dry cell Glass

rodOlive

oilR Extra

hightension

Metal Oliveoil

S Lowvoltagesupply

Carbon Oliveoil

Based on Table 8, state the suitableproperties for the set of apparatus toobserve the pattern of the electric field.

(i) Type of power supply

....................................................Reason

....................................................[2 marks]

(ii) Type of electrodes

...................................................Reason

....................................................[2 marks]

(d) Based on the answers in 8(c,which set of the apparatus is themost suitable to observe theelectrid field?

..........................................................[1 mark]

(e) State one reason why olive oil isused as liquid for the experiment.

..........................................................[1 mark]

FIZIKMOZAC 2010

7.2 RELATIONSHIP BETWEENCURRENT AND VOLTAGE

2. Question 1: MRSM 08Diagram 1 shows an electric circuitwhich is used to investigate therelationship between electric currentand potential difference across aconductor XY.

(a) What is the function of thevoltmeter?

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

(b) Underline the correct answer in thebracket to complete the sentencebelow. When the electric currentincreases,(i) The potential difference

(increases, decreases, remainunchanged)

(ii) The resistance will (increase,decrease, remain unchanged)

(c) State one physical quantity whichis kept constant in theexperiment.

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

7.2 RELATIONSHIP BETWEEN

Diagram 1 shows an electric circuitwhich is used to investigate therelationship between electric currentand potential difference across a

nction of the

...........................................................[1 mark]

Underline the correct answer in thebracket to complete the sentencebelow. When the electric current

The potential difference(increases, decreases, remain

[1 mark]

The resistance will (increase,decrease, remain unchanged)

[1 mark]

State one physical quantity which

..........................................................[1 mark]

3. Qustion 2: Johor 09Diagram 2.1 shows two constantan wireP and Q of the same length but ofdifferent cross-sectional area, beingused to carry out an experiment.

Initialy, the experiment is carried outwith P placed acros XY. After that, P isreplaced with Q and the experiment isrepeated. The V-I graph in Diagram 2.2shows the results obtained from theexperiment.

(a) Based on Diagram 2.1, comparethe cross sectinal area of wires Pand Q.

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

(b) Based on Diagram 2.2:(i) State how the resistance of

the constantant wire can beobtained.

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

Qustion 2: Johor 09Diagram 2.1 shows two constantan wireP and Q of the same length but of

sectional area, beingused to carry out an experiment.

Initialy, the experiment is carried outwith P placed acros XY. After that, P isreplaced with Q and the experiment is

I graph in Diagram 2.2shows the results obtained from the

Based on Diagram 2.1, comparethe cross sectinal area of wires P

............................................................[1 mark]

Based on Diagram 2.2:State how the resistance of

onstantant wire can be

...................................................[1 mark]

FIZIKMOZAC 2010

(ii) Determine the resistance ofconductor Q. Show on yourgraph.

[3 marks]

4. Question 4: Kelantan 09Diagram 4.1 shows a circuit used toinvestigate the relationship betweencurrent and potential difference accrossa constantants wire s.w.g 24 with lengthof 10 cm.

(a) Name the measuring instrumentslabeled X and Y in Diagram 4.1

X = ..................................

Y = ..................................

(b) (i) What is the relationship betweenthe reading of the measuringinstruments X and Y?

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

(ii) State the physics law involvedin 4(b)(i)

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

(c) The experiment is repeatedusing a constantan wire s.w.g 36with the same length. Diagram4.2 shows the graph V against Tfor the experiment.

Determine the resistance ofconductor Q. Show on your

[3 marks]

Diagram 4.1 shows a circuit used toinvestigate the relationship betweencurrent and potential difference accrossa constantants wire s.w.g 24 with length

Name the measuring instrumentslabeled X and Y in Diagram 4.1

[2 marks]

(i) What is the relationship betweenthe reading of the measuring

...........................[1 mark]

State the physics law involved

......................................................[1 mark]

The experiment is repeated byusing a constantan wire s.w.g 36with the same length. Diagram4.2 shows the graph V against T

Based on graph in Diagram 4.2;(i) What is the physical quantity

represented by the gradient ofthe graph?

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

(ii) Which of the constantan wirehas the highest resistance?Why?

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

5. Question 8: Kedah 08(a) State Ohm’s law

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

(b) Diagram 8.1 shows a graph ofcurrent, I, against potentialdifference, V, of a diode.

Based on graph in Diagram 4.2;What is the physical quantityrepresented by the gradient of

....................................................[1 mark]

Which of the constantan wirehas the highest resistance?

....................................................[1 mark]

Question 8: Kedah 08

............................................................[1 mark]

Diagram 8.1 shows a graph ofcurrent, I, against potentialdifference, V, of a diode.

FIZIKMOZAC 2010

(i) State whether the ohm’s law isobeyed by the diode.

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

(ii) Give a reason why there is nocurrent flowing through the diodewhen the potential difference isbetween 0 V and -2 V.

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

(iii) What is the resistance of the diodewhen the potential difference is 2V?

(c) Identical light bulbs, each ofresistance R Ω are connected in three circuits as shown in Diagram 8.2.

The rheostat in each circuit is adjustedand the potential difference, V, againstcurrent, I, graphs are plotted for eachcircuit. The graph for each circuit ishown in Diagram 8.3

State whether the ohm’s law is

...........................................................[1 mark]

Give a reason why there is nocurrent flowing through the diodewhen the potential difference is

....................................................[1 mark]

What is the resistance of the diodewhen the potential difference is 2

[2 marks]

ight bulbs, each ofΩ are connected in three

circuits as shown in Diagram 8.2.

The rheostat in each circuit is adjustedand the potential difference, V, againstcurrent, I, graphs are plotted for eachcircuit. The graph for each circuit is

(i) Match the graphs K, L and M tothe circuits X, Y and Z.

CircuitXYZ

(ii) Explain your answers in (c)(i).

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

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

(iii) Calculate the value of R.

7.3 SERIES AND PARALLEL CIRCUIT

6. Question 3: Kelantan 08Diagram 3.1 shows a photograph of anelectric circuit. The circuit containsfour identical bulbs connected to fouridentical new dry cells.

Diagram 3.1

(a) What is the type of the circuit?

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

Match the graphs K, L and M tothe circuits X, Y and Z.

Graph

[3 marks]

Explain your answers in (c)(i).

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

................................................[2 marks]

Calculate the value of R.

[2 marks]

7.3 SERIES AND PARALLEL CIRCUIT

Question 3: Kelantan 083.1 shows a photograph of an

electric circuit. The circuit containsfour identical bulbs connected to four

Diagram 3.1

What is the type of the circuit?

.............................................................[1 mark]

FIZIKMOZAC 2010

(b) Draw an electric circuit diagram forthe above arrangement ofapparatus using appropriatesymbols.

[2 marks](c) Compare the brightness of the

lamps J, K, L and M. Tick (√) onebox below.

....... The brightness of lamp J >lamp K > lamp L > lamp M

....... The brightness of lamp L >lamp K > lamp J > lamp M

....... The brightness of lamp J =lamp K = lamp L = lamp M

[1 mark]

(d) Give one reason for your answer in(c).

.............................................................[1 mark]

(e) Explain why the circuit above isused in the house lighting circuit.

............................................................[1 mark]

7. SBP 09: Question 8Diagram 8.1 and Diagram 8.2 showsthree identical filament bulbs marked6V, 12W arranged in two different waysand connected to a battery 6 V .

Diagram 8.1 Diagram 8.2

(a) What is meant by 6V,12W ?

.......................................................[ 1 mark ]

(b)State the type of circuit inDiagram 8.1 and 8.2

Diagram 8.1: ..........................

Diagram 8.2: ...........................[ 2 marks ]

(c) The bulbs in Diagram 8.2 arebrighter than the bulbs inDiagram 8.1. Explain youranswer .

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

......................................................[ 2 marks ]

(d)The resistance of each bulb inDiagram 8.1 and Diagram 8.2 is4 Ω. Determine the current flowin each bulb.Diagram 8.1:

(i) Diagram 8.2:

[ 4 marks ]

(e)A student wants to design anincubator. Bulbs are used toheat up the incubator.(i) Between the circuit in

Diagram 8.1 and in Diagram8.2, which circuit is the mostsuitable to be used by thestudent to heat up theincubator.

................................................[1 mark]

FIZIKMOZAC 2010

(ii) Give two reasons for youranswer in 8(e)(i).

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

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

7.4 ELECTROMOTIVE FORCE ANDINTERNAL RESISTANCE

8.Figure 10.1 (a) and Figure 10.2 (a) showtwo circuits used to investigate therelationshipbetween potential difference andelectric current.Figure 10.1(b) and Figure 10.2(b) showthe potential difference against electriccurrent graph respectively for Figure10.1(a) and Figure 10.2(b).

(a) What is meant by electric current?

V

00

V

V

Figure10.1(a)

V

Figure10.1(bRajah

0

0

Figure10.2(a)

Figure10.

Give two reasons for your

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

.................................................[2 marks]

ELECTROMOTIVE FORCE ANDINTERNAL RESISTANCE

Figure 10.1 (a) and Figure 10.2 (a) showtwo circuits used to investigate the

potential difference and

Figure 10.1(b) and Figure 10.2(b) showthe potential difference against electriccurrent graph respectively for Figure

What is meant by electric current?

(b) Compare the placement of thevoltmeter in Figure 10.1(a) andFigure 10.2(a). Then compare therelationship between potentialdifference and current for bothgraphs. Explain the results shownin both graphs. Hence state therelated physics law and conceptsapplicable in each situation.

7.5 ELECTRICAL ENERGY

9. Question 7: Kedah 09Diagram 7 shows an electric motorlifting a 2.0 kg load. When the motor isswitched on, the load moved through aheight of 1.5 m in 2.5 s with constantspeed. The current flowing in thecircuit is 1.7 A and the potentialdifference across the motor is 10.

(a) State the changes in energy thatoccure when the motor is switchedon.

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

(b) Calculate:(i) The electrical power

supplied when the motor islifting the load.

I

I

Figure10.1(b)Rajah

Figure10.2(b)

[ 1 mark ]

Compare the placement of thevoltmeter in Figure 10.1(a) andFigure 10.2(a). Then compare the

ip between potentialdifference and current for bothgraphs. Explain the results shownin both graphs. Hence state therelated physics law and conceptsapplicable in each situation.

[ 5 markah ]

7.5 ELECTRICAL ENERGY

Question 7: Kedah 09iagram 7 shows an electric motor

lifting a 2.0 kg load. When the motor isswitched on, the load moved through aheight of 1.5 m in 2.5 s with constantspeed. The current flowing in thecircuit is 1.7 A and the potentialdifference across the motor is 10.0 V.

State the changes in energy thatoccure when the motor is switched

.............................................................[1 mark]

The electrical powersupplied when the motor islifting the load.

[2 marks]

FIZIKMOZAC 2010

(ii) The output power of themotor when the loadmoved throught a height of1.5 m in 2.5 s.

(iii) the efficiency of thmotor.

(c) If some of the load is removedwhile the motor is still lifting theload, what change i observed onthe ammeter? Explain youranswer.

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

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

(d) Suggest one way to increase theefficiency of the motor.

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

10.Question 8: Johor 07Diagram 8.1 shows an electric iron withspecification of 240 V, 1000 W.

DIAGRAM 8.1

(a) What is meant by specification 240V, 1000 W?

……………………………………………

…………………………………………...

The output power of themotor when the loadmoved throught a height of

[2 marks]

the efficiency of the eletric

[2marks]

If some of the load is removedwhile the motor is still lifting theload, what change i observed onthe ammeter? Explain your

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

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

Suggest one way to increase the

..........................................................[2 mark]

an electric iron withspecification of 240 V, 1000 W.

What is meant by specification 240

……………………………………………..

………………………………………….....

(b) The electric iron is connected to a240 V supply and used to ironclothes for 30 minutes.

Calculate:(i) the current that passes through

the heating element in the iron.

(ii) the cost of using the electric ironin 30 days, if the cost ofelectricity by Tenaga Nasion23 cents per kW h for first 200units.

(c) A student conducts an experimentto compare the heating effect ofbread toasters P, Q and R. Twoslices of bread is toasted each time.Table 8.1 shows the result of theexperiment.

Breadtoaster

Potentialdifference,

V/v

Current,

P 240Q 240R 240

TABLE 8.1

[1 mark]

) The electric iron is connected to asupply and used to iron

minutes.

the current that passes throughthe heating element in the iron.

[2 marks]

the cost of using the electric ironin 30 days, if the cost of

Tenaga Nasional is23 cents per kW h for first 200

[2 marks]

A student conducts an experimentto compare the heating effect ofbread toasters P, Q and R. Twoslices of bread is toasted each time.Table 8.1 shows the result of the

Current,I/A

Time totoast 2

slices ofbread,

t/s6.0 905.0 1504.0 120

TABLE 8.1

FIZIKMOZAC 2010

(i) Calculate the energy supplied byeach of bread toaster to toast thebread.

(ii) Using your answer in (cwhich bread toaster is mostsuitable. Give two reasons foryour answer.

………………………………………

………………………………….......

…………………………………………

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

11.Question 8: Trengganu 08Diagram 8.1 shows an electric kettlewith specification of 240 V, 1.2 kW.

(a) What is meant by the label 240V,1.2 kW?

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

(b) Calculate

(i) the current flows through theelectric kettle.

Calculate the energy supplied byeach of bread toaster to toast the

[4 marks]c)(i), state

which bread toaster is mostGive two reasons for

…………………………………………

…………………………………...........

…………………………………………

...........................................................[3 marks]

Question 8: Trengganu 08Diagram 8.1 shows an electric kettlewith specification of 240 V, 1.2 kW.

What is meant by the label 240V,

............................................................[1 mark]

the current flows through the

[2 marks]

(ii) the resistance of the heatingelements in the kettle.

(c) Four electric kettles W, X , Y and Zwith specification 240 V, 2 kW aremade from the materials withdifferent characteristics.shows the characteristics of thematerials.

Kettle

The characteristics ofthe materials are usedin the heating element

in the kettle

Boilingpoint/oC

Resistivity/

W 3501

X 1085

Y 3387

Z 1064

(i) Based on the characteristics ofthe heating elements in Table8.1, suggest two electric kettlesare suitable to heat water. Givethe reason for your answer.

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

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

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

the resistance of the heatingelements in the kettle.

[2 marks]

Four electric kettles W, X , Y and Zwith specification 240 V, 2 kW are

the materials withdifferent characteristics. Table 8.1shows the characteristics of the

The characteristics ofthe materials are usedin the heating element

in the kettle

Resistivity/10-8 m

Fuse

13.5 8A

5.2 10 A

12.4 10 A

4.63 8A

Based on the characteristics ofthe heating elements in Table8.1, suggest two electric kettlesare suitable to heat water. Givethe reason for your answer.

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

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

......................................................[3 marks]

FIZIKMOZAC 2010

(ii) Based on the fuse used in theTable 8.1 , suggest two electrickettles are suitable to heat water.Give the reason for your answer.

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

........................................................[2 marks]

(iii) Using your answer in (b)(i) and(b)(ii), suggest which electrickettle is the most suitable toheat water. Give the reason foryour answer.

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

........................................................[2 marks]

12.Melaka 09: Question 8Diagram 8.1 shows an electric motorused to lift a load.

(a) State the energy transformationwhen the switch is closed.

..........................................................[1 mark]

(b) The mass of the load is 1.5 kgand is lifted to a height 1.5 m in5.0 s. The reading of the ammeter

is 1.2 A and the reading of thevoltmeter is 5.0 V.Calculate(i) Input energy to the motor

[2 marks]

(ii) Output energy of themotor.

[2 marks]

(c) Computer, air condition andwater heater are common homeelectrical appliances. Table 8shows the power rating and thetime consumption for a day forthese electrical appliances.

Appliance Power,PW

Time, tHr

Voltage,V

Computer 200 1 240

Aircondition

200 1 240

Waterheater

3 800 ½ 240

Calculate energy consumption for eachelectrical appliances for one week.

(i) Computer

(ii) Air condition

(iii) Water heater[5 marks]

FIZIKMOZAC 2010

(d) (i) Based on the answers in8(c), which electrical applianceshould be less time during ‘saveelectricity’ campaign.

....................................................[1 mark]

(ii) State one reason for the answerin 8(d)(i).

.......................................................[1 mark]

ESSAY QUESTIONS:13.SBP 07 Section B

Figure 10.1(a) and Figure 10.1(b) showphotographs of two electric circuits.Each circuit contains two identical newdry cells marked 1.5 V, a 2 ohm resistorand an ammeter.

Figure 10.2(a) and Figure 10.2(b) showthe reading of the ammeter for eachcircuit respectively.

(a) State the energy transformationsthat take place in the dry cell.

[1 mark]

(b) Observe Figure 10.1 and Figure10.2. Compare the arrangement ofdry cells in the circuit, the voltagesupplied and the reading of theammeter.State the relationship between theenergy transferred to flow theelectric charges around the circuitand(i) the voltage supplied(ii) the current flowing around the

circuit

[5 marks](c) Explain why it is more dangerous

to touch the live wire of a mainssupply, rather than the neutralwire.

[4 marks]

(d) Diagram 10.3 shows a cabinwiring consisting of a filamentlamp, an air conditioner and anelectric kettle. The electric supplyenters the cabin via meter andfuse box.

Diagram 10.3

L – Live wireN – Neutral wireE – Earth wire

Using your knowledge on electricity andDiagram 10.3, suggest and explainsuitable designs or ways to

FIZIKMOZAC 2010

(i) make the cabin wiring moreeffective

(ii) protect electric appliances fromdamage

(iii) prevent electric shock(iv) increase energy efficiency

[10 marks]

14.Trengganu 07:Section BDiagram 10.1 and Diagram 10.2 showtwo identical resistors which hasresistance R connected to theammeters, voltmeters, switches andbatteries with different ways.

Diagram 10.1

Diagram 10.2

When the switch is on, the ammetersand the voltmeters show a reading.

(a) What is meant by current?[1 mark]

(b) With reference to Diagram 10.1and Diagram 10.2, compare thetype of circuit connections, thereading of ammeters, the readingof voltmeters and the effectiveresistance of the circuits.Relate the current flows in a circuitwith the effective resistance tomake a deduction regarding therelationship between type of acircuit connection and theeffective resistance.

[6 marks]

(c) One identical resistor isconnected parallel to theresistors in Diagram 10.2. Explainwhat happens to the reading ofammeter and voltmeter.

[3 marks]

(d) Diagram 10.3 shows the lamps ina domestic lightning circuit areconnected in parallel.

Diagram 10.3

FIZIKMOZAC 2010

The circuit is not complete and notefficient for electrical energyconsuming and less safety.Suggest modifications that need to bedone to the circuit to improve safety,produce the lamps lights up withnormal brightness and to increases theefficiency of electrical energyconsuming.

[10

15. Kedah 07 (Section C)(a) Draw a diagram to show how 3

resistors can be connected inseries.

(b) A student plans to fix a lamp inhis room. Table 12.1 shows thefeatures of 4 different types oflamps.

Type oflamp

Po-werP/W

Effi-ciency

Lifespanhours

Compactfluorescent

lamp

18 50 % 7000

Filamentlamp

75 12 % 1000

Longfluorescent

lamp

20 45 % 14000

Roundfluorescent

lamp

24 40 % 10000

Explain the suitability of eachTable 12.1 and then determine the mostsuitable lamp to be used. Give a reasonfor your choice.

[10

(c) A 5 resistor and a 10are connected in parallel to a 9 Vpower supply.

The circuit is not complete and not

t modifications that need to bedone to the circuit to improve safety,

lamps lights up withnormal brightness and to increases theefficiency of electrical energy

[10 marks]

Draw a diagram to show how 3resistors can be connected in

[1 mark]

A student plans to fix a lamp inhis room. Table 12.1 shows thefeatures of 4 different types of

Lifespanhours

price

7000 High

1000 Low

14000 Medium

10000 high

Explain the suitability of each feature indetermine the most

suitable lamp to be used. Give a reason

[10 marks]

resistor and a 10 resistorare connected in parallel to a 9 V

Calculate

(i) the effective resistance,(ii) the current in the 5(iii) power dissipated by the 10

resistor.

16.Understanding: Teknik 07Diagram 12.1 and 12.2 shows twoidentical bulbs connected to one celland two dry cell respectively. The bulbconnected to two dry cells lights upbrighter

DIAGRAM 12.2

(a) (i) What is meant by the value “ 9 V ”labelled on the dry cell?

(ii) Explain why the bulb connectedto two dry cells is brighter.

the effective resistance,the current in the 5 resistor,

dissipated by the 10

[5 marks]

Understanding: Teknik 07Diagram 12.1 and 12.2 shows twoidentical bulbs connected to one cell

ry cell respectively. The bulbconnected to two dry cells lights up

DIAGRAM 12.2

What is meant by the value “ 9 V ”labelled on the dry cell?

[ 1 marks ]

Explain why the bulb connectedto two dry cells is brighter.

[ 3 marks ]

FIZIKMOZAC 2010

17.Section B: N9 08The lamps in a house are connected inparallel to the main supply.Diagram 10 shows two bulbs areconnected to a switch and a dry cell.(i) Based on Diagram 10, draw the

electric circuit diagram in youranswer sheet.

[3 marks]

Diagram 10Rajah 10

(ii) Each bulb is labelled 1.5V, 3W.What is meant by “1.5V , 3W” ?

[2marks]

(iii) Compare the brightness of bulb Aand bulb B, when the switch is on.

[1 marks]

(iv) Determine the current in thewhen the switch is on?

(v) Calculate the energy consumed bythe two bulbs if they are switchedon for 1 hour.

(b) As an engineer you are given thetask of determine the type ofwire that is suitable to be used forconnecting electric devices in ahouse.

The lamps in a house are connected in

Diagram 10 shows two bulbs ared a dry cell.

(i) Based on Diagram 10, draw theelectric circuit diagram in your

[3 marks]

(ii) Each bulb is labelled 1.5V, 3W.What is meant by “1.5V , 3W” ?

[2marks]

(iii) Compare the brightness of bulb Aand bulb B, when the switch is on.

[1 marks]

(iv) Determine the current in the circuit

[2marks]

(v) Calculate the energy consumed bythe two bulbs if they are switched

[2marks]

(b) As an engineer you are given thetask of determine the type of

hat is suitable to be used forconnecting electric devices in a

Explain the suitability of thefollowing aspect of the wire.

(i) resistance of wire(ii) melting point of wire(iii) density of wire(iv) rate of rusting of wire(v) rate of expansion

18.Section B: Johor 08Diagram 10.1 and Diagram 10.2 showthe bulbs connection at the fruit stores.The bulbs and the battery in both thestore are identical.

Diagram 10.1

Diagram 10.2

Explain the suitability of thefollowing aspect of the wire.

resistance of wiremelting point of wire

rate of rusting of wirerate of expansion of wire

[10 marks]

Section B: Johor 08Diagram 10.1 and Diagram 10.2 showthe bulbs connection at the fruit stores.The bulbs and the battery in both the

Diagram 10.1

Diagram 10.2

FIZIKMOZAC 2010

(a) (i) What is meant by a potentialdifferent?

(ii) Draw a circuit diagram for eachcircuit and label the type ofcircuit.

[4 marks]

(b) Using Diagram 10.1 and 10.2,compare the brightness of thebulbs. Relate the brightness ofthe bulb, the potential differentand the current flow for the bulbsto deduce a relevant physicsconcept.

(c) Diagram 10.3 shows an elekettle which is a rated at 240 V,2 000 W and connected by aflexible cable to a three-

Suggest modifications that can bemade to the electric kettle inDiagram 10.3 so that it can boilwater faster and has better safety.

[10

t by a potentialdifferent?

[1 mark]

Draw a circuit diagram for eachcircuit and label the type of

[4 marks]

gram 10.1 and 10.2,compare the brightness of thebulbs. Relate the brightness ofthe bulb, the potential differentand the current flow for the bulbsto deduce a relevant physics

[5 marks]Diagram 10.3 shows an electrickettle which is a rated at 240 V,2 000 W and connected by a

-pin-plug.

Suggest modifications that can bemade to the electric kettle inDiagram 10.3 so that it can boilwater faster and has better safety.

[10 marks]

19.Section C: Melaka 08(a) Diagram 11.1 (a) shows a filament

bulb labeled “240 V. 80 W”.Diagram 11.1 (b) shows a graph ofpotential difference against currentfor two materials, Y and Z. One ofthe materials will be chosen asfilament in a bulb.

i) What is meant by “240 V, 80 W?”

ii) Based on the graph in Diagram11.1(b), compare the resistance ofmaterials Y and Z.

Choose the more suitable materialto use as a filament of the bulb.Explain your choice.

b) As a researcher, your duty is tostudy the characteristics of amaterial to make a heating elementof a water heater. You are givenfour choices of heating elements J,K, L and M. Table 1 shows thecharacteristics of the four heatingelements.

Section C: Melaka 08Diagram 11.1 (a) shows a filamentbulb labeled “240 V. 80 W”.Diagram 11.1 (b) shows a graph ofpotential difference against currentfor two materials, Y and Z. One ofthe materials will be chosen as

What is meant by “240 V, 80 W?”[1 mark]

Based on the graph in Diagram11.1(b), compare the resistance of

Choose the more suitable materialto use as a filament of the bulb.Explain your choice.

[4 marks]

er, your duty is tostudy the characteristics of amaterial to make a heating elementof a water heater. You are givenfour choices of heating elements J,K, L and M. Table 1 shows thecharacteristics of the four heating

FIZIKMOZAC 2010

You are required to determine themost suitable heatingelement.Study the specificationsof all the four metals based onthe following aspects.

- The cross sectional area- Melting point- Specific Heat Capacity- Length of the heating element

[10

c) Three resistors with resistance 12, and 3 respectively areconnected to 6 V battery as shownin Diagram 11.2.

Based on Diagram 11.2Calculate

(i) Effective resistance

(ii) Power dissipated by 2Ωresistor

termine the

specificationsof all the four metals based on

The cross sectional area

Specific Heat CapacityLength of the heating element

[10 marks]

sistance 1 ,respectively are

connected to 6 V battery as shown

Power dissipated by 2Ω

[5 marks]

20.Section C: Trengganu 09Diagram 12.1 shows a ping pong ballcoated with thin metal foil placedbetween a pair of parallel metal disc.When the EHT is switched on an electricfield is formed in between the metaldisc.

(a) What is meant by electric field?

(b) Explain what will happen to theping pong ball when it is broughtto touch the metal disc connectedto positive terminal of EHT?

(c) Diagram 12.2 shows four electriccircuits K,L,M and N with differentarrangement of bulbs and powersockets. The current is to beused in wiring a guard booth.You are required to determine themost suitable circuit to light upand supply the electrical power tothe booth. Study all the fourcircuits based on the followingaspects.(i) Safety feature(ii) Arrangement of bulb and

power sockets(iii) Position of the kilowat

meter and main fuse.

Section C: Trengganu 09Diagram 12.1 shows a ping pong ballcoated with thin metal foil placedbetween a pair of parallel metal disc.When the EHT is switched on an electric

formed in between the metal

What is meant by electric field?[1 mark]

Explain what will happen to theping pong ball when it is broughtto touch the metal disc connectedto positive terminal of EHT?

[4 marks]

Diagram 12.2 shows four electriccircuits K,L,M and N with differentarrangement of bulbs and powersockets. The current is to beused in wiring a guard booth.You are required to determine the

le circuit to light upand supply the electrical power tothe booth. Study all the fourcircuits based on the following

Safety featureArrangement of bulb andpower socketsPosition of the kilowat-hourmeter and main fuse.

FIZIKMOZAC 2010

(d) An electric toaster has a heatingelement of resistance 26.7current flowing through it while inuse is 9 A.(i) State the suitable fuse for the

toaster(ii) Calculate

- The supplied voltage- The power dissipated by the

toaster

21. Johor 09: Section CDiagram 12.1(a) and Diagram 12.1(b)show photographs of two electriccircuits. Each circuit contains twoidentical dry cells of e.m.f 1.5 V, aresistor R and an ammeter.

toaster has a heatingelement of resistance 26.7 Ω. The current flowing through it while in

State the suitable fuse for the

The supplied voltageThe power dissipated by the

toaster[5 marks]

Section CDiagram 12.1(a) and Diagram 12.1(b)show photographs of two electriccircuits. Each circuit contains twoidentical dry cells of e.m.f 1.5 V, aresistor R and an ammeter.

FIZIKMOZAC 2010

(a) What is meant by e.m.f? [1 mark]

(b) (i) Draw two electrical circuitdiagrams for photographs inDiagram 12.1(a) and Diagram12.1(b). [2 marks]

(ii) Name the dry cells connectionfor Diagram 12.1(a). [1 mark]

(iii) State the advantage of Diagram12.1(b) as compared to Diagram12.1(a). [1 mark]

(c) Table 12 shows four lamps P, Q,R and S with differentspecifications. You are asked toinvestigate the characteristic ofthe lamps as shown in Table 12.Explain the suitability of eachfeature of the lamp in Table 12.Determine the most suitable lampto be used as a reading lamp.Give reasons for your choice.

[10 marks]

Lamp P

CostRM 70

Power rating3000 W, 240 V

efficiency 75 %

Life time:4000 hours

Lamp Q

CostRM 30

Power rating36 W, 240 V

efficiency 80 %

Life time:8000 hours

Lamp R

CostRM 15

Power rating100 W, 240 V

efficiency 60 %Life time:6000 hours

Lamp S

CostRM 10

Power rating60 W, 240 V

efficiency 50 %Life time:1000 hours

(d) The power rating of lamp P is 200 W,240 V.(i) State the change of energy in

lamp P. [1 mark]

(ii) Calculate the electric currentand resistance for lamp P.[4 marks]

22. Mid-year Melaka 09: section CDiagram 11.1 shows a rheostat.Rheostat is a common device used inthe laboratory.

(a) What is the function of therheostat?

[1 mark]

(b) State one factor which effects thechanges of the resistance in therheostat.

[1 mark](c) Explain the working principle of the

rheostat .[3 marks]

FIZIKMOZAC 2010

(d) Diagram 11.2 shows an electrickettle used to boil water.

Table 11.3 shows the specifications offour wires of the same diameter that canbe used as a heating element of anelectric kettle.

Type DensityKgm-3

Meltingpoint /˚C

Oxid-tionrate

Resistivity/ Ωm

J 6 500 7 500 High 8.0 x 10-7

K 7 000 8 050 high 7.0 x 10-7

L 5 000 8 500 low 5.0 x 10-7

M 2 500 9 000 low 8.0 x 10-7

You are required to determine the mostsuitable wire and explain the suitabilityof the of the following aspects.

- Density- Melting point- Oxidation rate- Resistivity

[10 marks]

(e) Diagram 12.3 shows a graph ofcurrent against voltage for wire Aand wire B.

Based on Diagram 12.3(i) Name the wire with a

bigger diameter.[1 mark]

(ii) If the resistance of wireA is R1 and resistance ofwire B is R2, determinethe ratio of R1 : R2.

[4 marks]

23. MRSM 09: section CA typical torchlight with batteries isshown in Diagram 12.1.

(a) (i) Name the type of current usedin the torchlight. [1 mark]

FIZIKMOZAC 2010

(ii) Draw a circuit diagram forthe torchlight in Diagram12.1 [3 marks]

(b) Table 12.1 give details of theelectricity used by three electricalappliances in a household with a240 V mains power supply.

Appliance Appliancespecification

Durationswitched

on perday

(hours)Refrigerator 240 V,

1 kW24

Airconditioner

240 V,1.2 kW

10

Washingmachine

12 Ω 2

The electricity tariff for domestic useis given in Table 12.2Electrical energy Cost per unit

(RM)First 100 units 0.20

Second 100 units 0.29Above 200 units 0.25

Calculate,(i) The total energy consumed in

one day.(ii) The total energy consumed by

the appliance in on month (30days).

(iii) The total cost in one month(30 days)

[5 marks]

(c) Energy efficiency and safety areimportant considerations in thepurchase and use of electricalproducts and appliances.(i) A fuse in a power plug is labelled

“8 A’. What does the label 8Amean?

(ii) Table 12.3 shows four types ofpower socket remains extensionP, Q, R and S available in asupermarket.You are asked to evaluate thecharacteristics of the four powersocket extensions for normalhome use. Study the picturesand the specifications for thefollowing aspects.

- Safety- Energy efficiency- Control of electrical

applianceUsing physics concept, explainthe suitability of the powersocket extensions for eachaspect. Determine the mostsuitable socket extension andjustify your choice.

[10 marks]

FIZIKMOZAC 2010