Chapter 1: Introduction to Physics

Physical quantities QUANTITIES that are measurable

Base quantities PHYSICAL QUANTITIES that cannot be defined in terms of other physical
quantities

Derived quantities PHYSICAL QUANTITIES produced from the combination of base quantities through
multiplication, division or both

Scientific notation POWERS of the base number 10 to show a very large or small number
/ standard form

Prefixes GROUP OF LETTERS placed at the beginning of a word to modify its meaning,
which act as multipliers

Scalar quantity QUANTITY which has only magnitude (time, temperature, mass, volume, distance,
density, power)

Vector quantity QUANTITY which has both magnitude and direction (force, velocity, displacement,
acceleration, momentum)

Error DIFFERENCE between actual value of a quantity and the value obtained in
measurement

Systematic errors CUMULATIVE ERRORS that can be corrected, if the errors are known.
(zero error, incorrect calibration of measuring instrument)

Random errors ERRORS that arise from unknown and unpredictable variations in condition, and will
produce a different error every time. (human limitations, lack of sensitivity, natural
errors, wrong technique)

Zero error ERROR that arises when the measuring instrument does not start from exactly
zero

Parallax error ERROR in reading an instrument because the observer’s eyes and the pointer are
not in a line perpendicular to the plane of scale

Measurement PROCESS of determining value of a quantity using a scientific instrument with a

standard scale

Consistency ABILITY to register the same reading when a measurement is repeated (improve –
eliminates parallax error, greater care, not detective instrument)

Accuracy DEGREE to which a measurement represents the actual value (improve – repeat
readings, avoid parallax/zero error, high accuracy instrument)

Sensitivity ABILITY to detect quickly a small change in the value of a measurement

(thermometer – thin wall bulb, narrow capillary)

Inferences EARLY CONCLUSION that you draw from an observation or event using information
that you already have on it

Hypothesis GENERAL STATEMENT that is assumed to be true regarding the relationship

between the manipulated variable and responding variable
Chapter 2: Forces and Motion

Distance total route taken by a motion

Displacement CHANGE IN POSITION of an object from its initial position in a specified direction
Distance taken with consideration of direction

Speed RATE OF CHANGE of distance

Velocity RATE OF CHANGE of displacement

Acceleration RATE OF CHANGE of velocity

Mass AMOUNT of matter in the object

Inertia PROPERTY of matter that causes it to resist any change in its motion or state of rest

Momentum PRODUCT of mass and velocity

Force pulling or a pushing ACTION on an object

Action which will alter the state of motion of a body in a straight line

Impulse Change of momentum

Impulsive force RATE OF CHANGE in momentum

LARGE FORCE which acts over a very short time interval

Gravity FORCE originated from centre of the Earth that pulls all objects towards the ground

Free fall FALLING of an object without encountering any resistance from a height towards the
earth with an acceleration due to gravity

Forces in equilibrium An object is said to be in a state of equilibrium when forces act upon an object and it
remains stationary or moves at a constant velocity

Resultant force SINGLE FORCE which combines two or more forces which act on an object

Work Work is done when a force causes an object to move in the direction of the force.

Energy Potential or the ability to do work

Gravitational PE ENERGY STORED in the object because of its height above the earth surface

Elastic PE ENERGY STORED in the object as a result of stretching or compressing it

Kinetic energy ENERGY possessed by a moving object

Power RATE at which work is done

Rate of change of energy

Efficiency ABILITY of an electrical appliance to transform energy from one form to another
without producing useless energy or wastage

Elasticity Ability of an object to return to its original shape after an applied force is removed

Spring constant FORCE needed to extend a spring per unit length

Elastic limit MAXIMUM STRETCHING FORCE which can be applied to an elastic material before
it ceases to be elastic
PRINCIPLE

Hooke’s Law
Hooke’s law states that the force, F applied to a spring is directly proportional to the spring’s extension or
compression, x, provided the elastic limit is not exceeded.

Principle of conservation of energy

Principle of conservation of energy states that total energy in an isolated system is neither increased nor
decreased by any transformation. Energy cannot be created nor destroyed, but it can be transformed from one
kind to another, and the total amount stays the same.

Principle of conservation of momentum

The principle of conservation of momentum states that, in any collision or interaction between two or more
objects in an isolated system, the total momentum of the system will remain constant; that is, the total initial
momentum will equal the total final momentum.

Newton’s first law of motion

Newton’s first law of motion states that a body will either remain at rest or continue with constant velocity
unless it is acted on by an external unbalanced force.

Newton’s second law of motion

Newton’s second law of motion states that the acceleration a body experiences is directly proportional to the
net force acting on it, and inversely proportional to its mass. F =ma

Newton’s third law of motion

Newton’s third law of motion states that to every action there is an equal but opposite reaction.
Chapter 3: Forces and Pressure

Pressure FORCE acting normally per unit surface area

Gas pressure FORCE per unit area exerted by the gas particles as they collide with the walls of their
container (due to the rate of change of momentum)

Buoyant force The upthrust acting on an object due to the fluid displaced when an object is immersed

PRINCIPLE

Law of Floatation
Law of floatation states that the weight of an object floating on the surface of a liquid is equal to the weight of
water displaced by the object. (weight of object = weight of water displaced)

Pascal’s Principle
Pascal’s principle states that a pressure applied to a confined fluid is transmitted uniformly in all directions
throughout the fluid.

Archimedes’ principle
Archimedes’ principle states that the buoyant force on a body immersed in a fluid is equal to the weight of the
fluid displaced by that object (buoyant force = weight of water displaced)

Bernoulli’s principle
Bernoulli’s principle states that the pressure of a moving fluid decreases as the speed of the fluid increases,
and the converse is also true.
Chapter 4: Heat

Temperature DEGREE of hotness of an object

Thermometric property PHYSICAL PROPERTY of a substance which is sensitive to and varies linearly with
the temperature change

Thermal equilibrium A STATE when the net rate of heat transfer between the two objects are zero and
their temperature are the same

Heat capacity The amount of HEAT ENERGY required to raise the temperature of an object by 1°C

Specific heat capacity The amount of HEAT ENERGY required to increase the temperature of a mass of
1kg by 1°C

Latent heat The amount of HEAT ABSORBED OR RELEASED when a substance changes its
state without a change in temperature

Specific latent The amount of HEAT ENERGY required to change 1 kg of a substance from solid
heat of fusion state to liquid state without a change in temperature

Specific latent heat The amount of HEAT ENERGY required to change 1 kg of a substance from liquid
of vapourisation state to gaseous state, without a change in temperature

PRINCIPLE

Boyle’s Law
Boyle’s Law states that the pressure of a fixed mass of gas is inversely proportional to its volume provided the
temperature of the gas is kept constant (PV = k)

Pressure Law
The pressure law states that the pressure of a fixed mass of gas is directly proportional to its absolute
temperature (in Kelvin), provided the volume of the gas is kept constant (P/T = k)

Charles’ Law
Charles’ law states that the volume of a fixed mass of gas is directly proportional to its absolute temperature (in
Kelvin), provided the pressure of the gas is kept constant (V/T = k)
Chapter 5: Light

Refraction PHENOMENON where the direction of light is changed when it crosses the boundary
between two materials of different optical densities as a result of a change in the
velocity of light.

Apparent depth, d DISTANCE of the image from the surface of water (or the boundary between the two
mediums involved)

Real depth, D DISTANCE of the object from the surface of the water (or the boundary
between the two mediums involved)

Total internal TOTAL REFLECTION of a beam of light at the boundary of two mediums, when
reflection the angle of incidence in the optically denser medium exceeds a specific critical
angle

Critical angle GREATEST ANGLE OF INCIDENCE in the optically denser medium for which the
angle of refraction, r = 90°

Power of lens MEASURE OF ITS ABILITY to converge or diverge an incident beam of light

PRINCIPLE

Laws of Reflection
- the angle of incidence, i, is equal to the angle of reflection, r (i = r)
- the incident ray, normal and reflected ray will all lie in the same plane

Law of Refraction
- The incident ray and the refracted ray are on the opposite sides of the
normal at the point of incidence, all three lie in the same plane
- Obey snell’s law

Snell’s Law
The value of sin i/sin r is a constant.

IMAGE CHARACTERISTICS

Virtual an image which cannot be projected (focused) onto a screen

Real an image which can be projected (focused) onto a screen

Laterally inverted an image which left and right are interchanged

Upright an image which in vertical position

Diminished image formed is smaller than the object

Magnified image formed is larger than the object

Chapter 1 – Waves

Waves A disturbance that transfers energy between 2 points through vibrations in a medium, without
transferring matter between the 2 points

Wavefront LINE that joins all the points vibrating in phase

In phase = same direction, same displacement

Transverse Wave WAVE in which the vibration of particles in the medium is perpendicular to the
direction of propagation of the wave
(water waves, light waves, electromagnetic waves)

Longitudinal Wave WAVE in which the vibration of particles in the medium is parallel to the direction of
propagation of the wave (sound waves, ultrasound)

Coherent waves Waves that have the same frequency and with constant phase difference

Amplitude MAXIMUM DISPLACEMENT form its equilibrium position

Period TIME TAKEN to complete an oscillation, from one extreme point to the other and back to the
same position.

Frequency NUMBER OF COMPLETE OSCILLATIONS made by a vibrating system in one second

Wavelength, λ DISTANCE between successive points of the same phase in a wave

Damping DECREASE in the amplitude of an oscillating system is called damping.

(Internal damping: extension and compression of molecules
(External damping: frictional force/ air resistance)

Resonance Resonance occurs when a system is made to oscillate at its natural frequency by an external
force. The resonating system oscillates at its maximum amplitude.

Natural frequency The frequency of a system which oscillates freely without external force

Reflection of wave Change in the direction of wave that occurs when a wave strike an obstacle
(direction ≠ ; f = ; a ≠ ; λ = )

Refraction of wave Change in the direction of travel of the waves caused by the change of speed of the
waves as they pass through different mediums
(f = ; v ≠ ; λ ≠ ; direction ≠)

Diffraction of waves The spreading of a wave as it passes through a narrow slit or round a small obstacle
(f = ; λ = ; speed = ; v ≠ ; direction ≠)

Interference of waves SUPERPOSITION of two waves originating from two coherent sources
(coherent = same frequency, amplitude and in phase)

Constructive interference The superposition of 2 waves which are in phase to produce a resultant
wave of maximum amplitude

Destructive interference The superposition of 2 waves which are in phase to produce a resultant
wave of zero amplitude

Antinodal line Line joining all the points where constructive interference takes place.

Nodal line Line joining all the points where destructive interference takes place.
Sound waves Longitudinal waves in which the oscillations of air molecules take place in the
direction of wave travel
Electromagnetic waves PROPAGATING WAVES in space with electric and magnetic components.
These components oscillate at right angles to each other and to the direction
of propagation of wave.

Monochromatic light LIGHT with only one wavelength and colour

Loudness Amplitude of sound

Pitch Frequency of sound

Principle of superposition
Principle of superposition states that at any instant, the wave displacement of the combined motion of any
number of interacting waves at a point is the sum of the displacements of all the components waves at that
point.

Chapter 2 – Electricity

Charge, Q WORK DONE to move a unit of voltage in a circuit

Current, I RATE of flow of charge

Potential difference, V WORK DONE when 1 Coulomb of charge moves between 2 points in an electric field

Electric field Region surrounding a charged body

A FIELD in which electric charge experiences an electric force

Circuit CLOSED LOOP through which charge can continuously flow

Resistance, R RATIO of the potential difference across the conductor to the current flowing through
it

Superconductor Material whose resistance becomes zero when it is cooled below a certain
temperature called the critical temperature

Electromotive force (e.m.f.) TOTAL ELECTRICAL ENERGY supplied by a cell given to 1 C of charge
flowing through the cell

Power Amount of energy transferred in 1 second

Power rating RATE at which it consumes electrical energy.

Electrical energy Total energy supplied by a electrical source

“12 V, 15 W” When a potential difference of 12 V is connected across the --- , it will produce ----
energy of 15 J per second

PRINCIPLE

Ohm’s Law Ohm’s law states that the electric current, I flowing through a conductor is directly
proportional to the potential difference across the ends of conductor, if temperature and other
physical conditions remain constant.
Chapter 3 – Electromagnetism

Electromagnet DEVICE in which magnetism is produced by an electric current

TEMPORARY MAGNET which acts as a magnet when the current is switched on and
ceases to be a magnet when the current is switched off

Magnetic field REGION in which a magnetic material experiences a force as the result of a magnet
or a current-carrying conductor

Radial field MAGNETIC FIELD with the field lines pointing towards or away from the centre of a
circle.

Electromagnetic induction PRODUCTION of an electric current by a changing magnetic field (conductor

cuts across a magnetic flux –OR– a change of magnetic flux linkage with a
coil)

Root mean square VALUE of a steady current/ voltage, which would produce the same heating effect in
a given resistor.

Transformer EQUIPMENT to raise or lower the potential difference of an alternating current supply

PRINCIPLE

Faraday’s Law
The magnitude of the induced electromotive force (e.m.f.) is directly proportional to the rate of change of
magnetic flux linkage with the solenoid or the rate at which a conductor cuts through the magnetic flux.

Lenz’s Law
Lenz’s law states that an induced electric current always flows in such a direction so as to oppose the change
(or motion) producing it.
Chapter 4 – Electronics
Thermionic emission EMISSION of electrons from hot metal surface

Doping Adding a small amount of other substances or impurities to semiconductors to

increase its electrical conductivity

Work function MINIMUM ENERGY required to eject electrons from surface

Cathode ray fast moving ELECTRONS travel in a straight line in vacuum

Cathode ray oscilloscope measuring and testing INSTRUMENT used in study of electricity and
electronics

Conductor MATERIAL which allows current to flow thorugh them

Semiconductor MATERIAL whose electrical conductivity is between conductor and insulator

Insulator MATERIAL which does not conduct electric current

Junction voltage POTENTIAL DIFFERENCE acting from n-type to p-type material of a diode across
the depletion layer

Rectification CONVERSION of a.c. to d.c. by diode

Smoothing PROCESS where output is smoothed by connecting a capacitor across load the
acts as a reservoir and maintains potential difference across load

Logic gates ELECTRONIC SWITCHES with one or more inputs and one output.
Chapter 5 – Radioactivity

Atom An atom consists of a nucleus which is made up of protons and neutrons, with
electrons orbiting the nucleus.

Nuclide TYPE of nucleus with particular proton number and nucleon number

Proton number NUMBER of protons in the nucleus of an atom

Nucleon number NUMBER of protons and neutrons in an atom

Isotopes ATOMS the same element with the same proton number but different nucleon and
neutron number (similar chemical properties but differs in physical properties)

Radioactivity SPONTANEOUS DISINTEGRATION of unstable nucleus into a more stable nucleus

with the emission of energetic particles or protons

Radioactive decay The spontaneous and random emission of radioactive rays from unstable nucleus or
material to become more stable

Radioisotope ISOTOPE with unstable nucleus that tends to undergo radioactive decay

Half life TIME TAKEN for the activity of atoms to fall to half its original value
TIME TAKEN for half the atoms in a given sample to decay

Nuclear energy Energy released during the decay or reaction of the radioactive nucleus

Nuclear fission The splitting of a heavy nucleus into two or more lighter and smaller nuclei with the
release of energy.

Nuclear fusion The fusion of two or more small and light nuclei to form a heavier and larger nucleus.

PRINCIPLE

Einstein’s Principle of Mass-Energy Conservation

The change of energy is linked to the change of mass by the equation E=mc 2