March 11, 2012

WHAT IS GRAVITY?

1)     An object will fall to the surface of the earth because it is pulled down by the force of gravity.

2)     The pull or force of gravity also known as Earth's Gravitational Force




  3)     When an object falls without encountering any resistance and under the force       of gravity only, the object is said to be free falling object.

February 8, 2012

SYMBOLS OF ELECTRIC DEVICES



ENERGY

GRAVITATIONAL POTENTIAL ENERGY, PE = mass x gravity x height

ELASTICS POTENTIAL ENERGY , PE = (1/2) force ( extension)2

POTENTIAL ENERGY DEPENDS ON POSITION OF OBJECT. THE HIGHER THE POSITION OF OBJECT FROM GROUND, THE BIGGER THE POTENTIAL ENERGY.


WORK









WORK is define as product of force and displacement. W = F.s , 
SI Unit for Work is Nm or Joule.

MOMENTUM




PRINCIPLE OF CONSERVATION OF MOMENT.

August 1, 2011

LIST OF TERMS IN PHYSICS

CHAPTER SIX (WAVES)


ITEM
MEANING / DEFINITION
Wave motion
Perambatan gelombang
Wave motion carries energy from one place to another place in a medium without the transfer of the particles along the medium.
Wavefront
Muka Gelombang
A wavefront is a line or plane where the vibrations of every point on it are in phase
Transverse wave
Gelombang Melintang
A wave in which the vibration of particles in the medium is at perpendicular to the direction of propagation of the wave.
Longitudinal wave
Gelombang Membujur
A wave in which the vibration of particles in the medium is parallel to the direction of propagation of the wave.
Amplitude
Amplitud
The maximum displacement from its equilibrium position.
Period
Tempoh
The time taken to make one complete oscillation
Frequency, f
Frekuensi
The number of complete oscillations made by a vibrating system in one second
One complete oscillation
Satu ayunan lengkap
A complete oscillation may be referred as the movement of a vibrating system from one extreme position to the other and back to the same position.
Wavelength, λ
Panjang gelombang
The wavelength is the distance between successive points of the same phase in a wave.
Damping
Pelembapan
Damping occurs when an oscillating system loses energy due to frictional forces.
Forced oscillation
Ayunan paksa
Forced oscillation occurs when a system oscillates under the influence of an external driving force.
Natural frequency
Frekuensi asli
The frequency of a system when it oscillates freely.
Resonance
Resonans
Resonance occurs when a system oscillates at the maximum amplitude when the driving frequency is equal to the natural frequency of the system.
Reflection of waves
Pantulan gelombang
Reflection of waves is the change in direction of propagation when a wave strikes an obstacle.
Incident waves
Gelombang Tuju
The waves moving towards an obstacle.
Reflected wave
Gelombang Pantulan
The wave which has undergone a change in direction of propagation after reflection.
Angle of incidence
Sudut Tuju
The angle between the direction of propagation of the incident wave and the normal
Angle of reflection
Sudut pantulan
The angle between the direction of propagation of reflected wave and the normal.
Law of Reflection
Hukum Pantulan
The angle of incidence is equal to the angle of reflection

Refraction of waves
Pembiasan Gelombang
Refraction is the change of direction of propagation when the speed of a wave changes as it moves from one medium to another
Diffraction of wave
Pembelauan Gelombang
Diffraction of waves is the spreading of waves as they pass through an aperture or around the edge of an obstacle
Principle of superposition
Prinsip superposisi
The sum of the displacements of all the component waves at the point.
Coherent waves
Gelombang Koheren
Waves of the same frequency and are in phase.
Interference
Interferens
Superposition of two coherent waves constructively or destructively
Constructive interference
Interferens membina
Occurs when two waves that are in phase superimpose
to produce a wave with crests and troughs of maximum amplitude.
Destructive interference
Interferens memusnah
Occurs when two waves that are out of phase superimpose to produce zero resultant amplitude
Antinode
Antinod
A point where constructive interference occurs.
Node
Nod
A point where destructive interference occurs.
Sound wave
Gelombang bunyi
Sounds are longitudinal waves produced by vibrations such as the vibrations of the diaphragm of a loudspeaker, guitar string and tuning fork.
Loudness
Kenyaringan
The intensity of a sound as heard by an observer  (depends on the amplitude of the sound)
Pitch
Kelangsingan
The pitch of the sound is an indication of the sharpness of a sound (depends on the frequency of the sound)
SONAR
Sound Navigation and Ranging (SONAR) is a system used to detect underwater objects or to determine the depth of the water by means of an echo.
Electromagnetic waves
Gelombang elektromagnet
Electromagnetic waves are propagating waves in space with electric and magnetic components.


CHAPTER SEVEN (ELECTRICITY)


ITEM
MEANING / DEFINITION
Current
Arus
Current is the rate of flow of electric charge
Ampere, A
SI unit of current
Coulomb, C
A unit of charge
Electric field
Medan elektrik
An electric field is a region where an electric force acts on a particle with an electric charge.
Potential Difference
Beza keupayaan
Potential difference is defined as the work done to move a unit of charge from one point to another in an electric field.
Ohm’s Law
Hukum Ohm
The electric current flowing through a conductor is directly proportional to the potential difference across the ends of the conductor, if the temperature and other physical dimensions remain constant.
Ohmic Conductor
Konduktor Ohm
Material which obey Ohm’s Law
Non Ohmic Conductor
Konduktor bukan Ohm
Material which do not obey Ohm’s Law
Resistance
Rintangan
Resistance is defined as (potential difference)/(current)
Effective Resistance
Rintangan berkesan
The effective resistance is the combined resistance in the circuit.
Electromotive Force (e.m.f)
Daya gerak elektrik (d.g.e.)
The total energy supplied by a cell when one unit of charge flows through the cell.
Internal Resistance
Rintangan dalam
The resistance within a cell due to its electrolyte or electrodes
Electrical Energy
Tenaga elektrik
Energy supplied by a source of electricity (cell / battery) when current flows in a closed circuit.
Power
Kuasa
Power is the rate of transfer of electrical energy
Power Rating
Kadar kuasa
The power rating of an appliance denotes the rate at which it consumes electrical energy at a certain voltage



CHAPTER EIGHT (ELECTROMAGNETISM)


ITEM
MEANING / DEFINITION
Electromagnet
Elektromagnet
An electromagnet is a device in which magnetism is produced by an electric current. It is a temperory magnet. It acts as a magnet when the current is flow and ceases to be a magnet when the current is switched off.
Magnetic field
Medan magnet
A magnetic field is a region in which a magnetic materials experiences a force.
Catapult field
Medan lastik
The resultant field produced when a straight wire carries a current in a uniform magnetic field.
Direct current motor
Motor arus terus
A direct current motor is used to convert electrical energy into rotational kinetic energy.
Electromagnetic induction
Aruhan elektromagnet
The production of an electromotive force in a conductor due to a changing magnetic flux.  
Induced e.m.f.
D.g.e. teraruh
An emf produced in a conductor when there is a changing magnetic flux or cutting of magnetic flux by the conductor
Induced current
Arus teraruh
Induced current is produced in a circuit when there is a changing magnetic flux or cutting of magnetic flux by a conductor
Faraday's law
Hukum Faraday
The magnitude of the induced e.m.f  is directly proportional to the rate at which a conductor cuts through the magnetic flux.
Lenz's law
Hukum Lenz
Lenz's Law state that an induced electric current always flows in such a direction as to oppose the change in magnetic flux.
Direct current
Arus terus
Current which flows in one direction.
Alternating current
Arus ulang alik
Current which flows back and forth in two opposite directions
Transformer
Transformer
A device which steps up or steps down the voltage of an alternating current.
Step-up transformer
Transformer injak naik
A transformer that steps up voltage
Step-down transformer
Transformer injak turun
A transformer that steps down voltage
Ideal transformer
Transformer unggul
A transformer where the output power is equal to the input power and the efficiency is 100%
Transmission of electricity
Penghantaran elektrik
The transmission of electricity from the power station to consumers (industries and residential areas) by electric cables
National Grid Network
Rangkaian Grid Nasional
The national grid is a network of electrical cables connecting electrical power stations to consumers of electricity.



CHAPTER NINE (ELECTRONICS)


ITEM
MEANING / DEFINITION
Thermionic emission
Pemancaran termionik
A process of emitting electrons from a hot metal surface.
Cathode ray
Sinar katod
A beam of fast moving, high energy electrons
Semiconductor
Semikonduktor
Materials whose resistance is between those of good conductors and good insulators.
Doping
Pendopan
The process of adding a small amount of impurities into the semiconductors.
n-type semiconductor
Semikonduktor jenis-n
Semiconductor where the majority charge carriers are free electrons
p-type semiconductor
Semikonduktor jenis-p
Semiconductor where the majority charge carriers are holes
Semiconductor diode
Diod semikonduktor
A p-n junction device which conducts current in one direction only
Forward-biased
Pincang ke hadapan
A diode is forward biased when the p-end is connected to the positive terminal of the battery and the n-end is connected to the negative terminal of the battery.
Reverse-biased
Pincang songsang
A diode is reverse biased when the p-end is connected to the negative terminal of the battery and the n-end is connected to the positive terminal of the battery.
Rectification
Rektifikasi
To convert alternating current into direct current using diodes
Half-wave rectification
Rektifikasi separuh gelombang
The process of rectification using a diode which allows current flow in half of a cycle.
Full-wave rectification
Rektifikasi penuh gelombang
The process of rectification using four diodes to allow current to flow in a complete cycle and in the same direction.
Smoothing Capacitor
Kapasitor perata
A capacitor that is used to smoothen the output voltage of a rectification process
n-p-n transistor
Transistor n-p-n
A transistor which consists of a layer of p-type semiconductor sandwiched between two layers of n-type semiconductors.
p-n-p transistor
Transistor p-n-p

A transistor which consists of a layer of n-type semiconductor sandwiched between two layers of p-type semiconductors.
Logic gate
Get logik
A logic gate is an electronic switch with one or more inputs  and only one output.
Truth table
Jadual kebenaran
A truth table shows the results of every possible output given every possible input.
AND gate
Get DAN
A logic gate where the output is 1 only when both inputs are 1
NOT gate
Get TAK
A logic gate that inverts the input
Or gate
Get ATAU
A logic gate where the Output is 1 except when both inputs are 0

CHAPTER TEN (RADIOACTIVITY)


ITEM
MEANING / DEFINITION
Nucleus
Nukleus
The small core of the atoms which contains the protons and neutrons
Nucleon
Nukleon
Protons and neutrons
Proton number, Z
Nombor proton
The number of protons in the nucleus of an atom
Nucleon number, A
Nombor nucleon
The total number of protons and neutrons in an atom.
Nuclide
Nuklid
A nuclide is one type of nucleus with a particular proton number and a particular nucleon number.
Isotope
Isotop
Atoms of an element which have the same proton number but different nucleon numbers
Radioisotope
Radioisotop
Isotopes with unstable nuclei
Radioactivity
Radioaktiviti
Radioactivity is the spontaneous disintegration of unstable nucleus into a more stable nucleus with the random emission of radiation.
Radioactive decay
Reputan radioaktif
Radioactive decay is a process where an unstable nucleus becomes a more stable nucleus by emitting radiation
Alpha decay
Reputan alfa
A radioactive decay where an alpha particle is emitted
Beta decay
Reputan beta
A radioactive decay where a beta particle is emitted
Gamma decay
Reputan gama
A radioactive decay where gamma rays are emitted
Half life
Setengah hayat
The time taken for mass or activity of a radioactive substance to become half its original value
Atomic mass unit (a.m.u)
Unit jisim atom
The atomic mass unit (a.m.u) is used to measure the masses of atomic particles.
Nuclear fission
Pembelahan nuklear
A process involving the splitting of a heavy nucleus into two lighter nuclei and several neutrons at the same time
Chain reaction
Tindak balas berantai
A chain reaction is a self-sustaining reaction in which the neutrons produced in a reaction can initiate another similar reaction.
Nuclear fusion
Pelakuran nuklear
Nuclear fusion is the combining of two lighter nuclei to form a heavier nucleus
Nuclear reactor
Reaktor nuklear
A nuclear reactor produces tremendous amount of energy through nuclear fission.