Tuesday, November 27, 2018

SPM 2018

Rujuk kepada nota seminar dan nota intensive

Kertas 2
1) Bacaan pada voltmeter/ammeter, ralat sifar and paralaks
2) Gerakan objek pada halaju malar, keseimbangan daya, daya bersih sifar
3) Muatan haba tentu, pengiraan dan graf pemanasan
4) Rektifikasi gelombang penuh, paparan OSK dan pengiraan voltan puncak dan frekuensi
5) Sifat - sifat imej terhadap kanta cekung/cembung, fungsi kanta pada jarak objek tertentu
6) Kelektromagnetan, arus aruhan dalam gegelung
7) Elektrik, pengiraan kos penggunaan dalam pemanas
8) Tekanan cecair
9) Archimedes' principle
10) Sound wave diffraction
11) Radioactivity, detector
12) ???

Kertas 3
1) Resultant force, F = ma
2) Charles' law
3) Ohm's law
4) Electromagnetism

Good luck and all the best !!!!!

Saturday, November 24, 2018

Answer for The Bengkel 2018


NO. SOALAN
JAWAPAN
MARKAH
9
(a)
(i)
Define pressure.
Force per unit area

1


(ii)
State the observation and analysis correctly

·       Plastic bottle in Diagram 9.1 inflates // Plastic bottle in Diagram 9.2 crumple
·       Diagram 9.1 higher altitude // Diagram 9.2 lower altitude
·       Volume of the gas in Diagram 9.1 is greater // Volume of the gas in Diagram 9.2 is less
·       Atmospheric pressure in Diagram 9.1 is  less // Atmospheric  pressure in Diagram 9.2 is greater
·       The pressure of the gas in the bottle in Diagram 9.1is equal to the pressure of the gas in the bottle in Diagram 9.2.

State the conclusion correctly

·       The greater the atmospheric pressure, the lesser the volume of the gas
·       The higher the altitude, the lower the atmospheric pressure

1

1

1

1


1




1

1
Max: 5

(b)

State the explanation why aerosol must be kept away from fire correctly

·       The aerosol can explodes
·       The greater the temperature, the greater the kinetic energy molecules of gas
·       Greater frequency of collision between the molecules and the wall of the container.
·       The greater impulsive force
·       The greater gas pressure
·       F α P



1
1

1

1
1
1
Max: 4






(c)

State the suggestions and explanations correctly

The body of hand air pump made of stronger material.
Withstand high pressure // Not break easily

The size of cylindrical body is large // Large diameter
Pump up larger volume of air.

Install Bourdon Gauge
Measure the pressure of air correctly

Body made of high specific heat capacity of material.
Not easy heat up // Hot slower

Stronger piston
Not easily break

Body made of low density of material.
Lighter // Light // Portable // Smaller mass

Tight connection between hose valve and tire vale
Prevent leakage of air pressure

Flexible hose
Bend easily

Longer handle
Easier to hold

Hand air pump powered by motor
More efficient // Pump air faster


1
1

1
1

1
1

1
1

1
1

1
1

1
1

1
1

1
1

1
1

Max: 10



FULL MARKS
20



NO. SOALAN
JAWAPAN
MARKAH
10
(a)

State the meaning of coherent sources.
Sources of waves which produce waves that vibrates with same frequency and same phase / constant difference phase.
1

(b)
(i)
Distance between two loud speakers in Diagram 10.1 < Diagram 10.2 // vice-versa.

Distance between two consecutive loud sounds in Diagram 10.2 < Diagram 10.1 // vice-versa.


Frequency of sound wave in Diagram 10.1 and Diagram 10.2 are equal.

The higher the distance between two loud speakers, the lower the distance between two consecutive loud sounds.
1




1


1

1


(ii)
Name the phenomenon involved.
Inteference.
1

(c)

Explain student P, Q and R can hear the sound.
Diffraction of waveoccured //
The waves spread around the corner.

Explain why student P can not hear the sound clearly compare to the student R.
The amplitude of sound wave hear by student R is greater,
More sound energy received.

Suggest one way so that student P can hear the sound clearly.
Increase the volume // High amplitude of sound wave

1



1
1


1

(d)

Aspects
Explanation
Ultrasonic waves // very  high frequency of sound wave
high frequency // high energy wave
High frequency
High energy // able to penetrate the deep sea // able to travel further
Short wavelength
Less diffracted // Travel in narrow beam  // less energy loss
Phenomenon  Reflection of wave
To produce echo // reflected of ultrasonic waves
Transmitter / receiver // Transducer
To transmit wave / to receive wave
1,1


1,1

1,1


1,1


1,1



FULL MARKS
20



NO. SOALAN
JAWAPAN
MARKAH
11
(a)

Name the physics principle involved.
Archimedes’ Principle
1

(b)

Explain why the ship can float in sea water.
Balance force
Buoyant force = weight of the ship.
1
1

(c)
(i)
State the purpose of plimsoll lines.
To ensure the ship will not be overload.
1


(ii)
State why plimsoll lines have many levels.
Different water zone has different density of water.
1

(d)

Explain the suitable characteristics.
Modification
Explanation
Streamlined shape
To reduce water resistance
High total mass of ship
To increase the stability of the ship
High width of ship base
Increase the vloume of the water displaced
High volumes of air space in the ship
Greater buoyant force
StructureW
(describe all characteristics)
1,1

1,1
1,1
1,1

1,1

(e)
(i)
Calculate the volume of water displaced.
V of water displaced by the load and the wooden block = V wooden block
V wooden block = 2.5 kg / 550 kg m-3
                         = 0.00455 kg
1
1


(ii)
Calculate the mass of the load X.
W load + W wooden block = W water displace
W load = (1000 kg m-3 x 0.00455 kg x 10 m s-2) – (2.5 kg x 10 m s-2)
            = 20.5 N
Mass load = 2.05 kg
1
1
1



FULL MARKS
20



NO. SOALAN
JAWAPAN
MARKAH
12
(a)

State the meaning of electromagnetic induction.
The produce of induced current when a wire cutting a magnetic flux.
1

(b)

Explain briefly the working principle of a direct current generator.
External force is applied
Operating based on electromagnetic induction.
When the coil horizontal, the wire cut the magnetic flux.
Current is produced.
Use Faraday Law
Use commutator


1
1
1
1
1
1
Max: 4

(c)

Explain the suitablity for construction of direct current generator.
Criteria
Explanation
High number of turns
Increase the speed
Coil mounted on laminated soft iron core
Concentrates the magnetic flux on the coil
Use commutator
Produce direct current output
Curve-shaped magnet
Produce radial magnetic field
Generator R
(describe all criteria)
1,1
1,1
1,1
1,1
1,1
1,1

(d)
(i)
Name the type of transformer used.
Step-up transformer



(ii)
Calculate the current flow in the bulb.
I = 0.25A

1
1


(iii)
Calculate the number of secondary coil.
N = 800 turns
1

1



FULL MARKS
20