PHYSICS IGCSE 2012 EXAM REVISION NOTES
By Samuel Lees and Adrian Guillot
1. General physics
1.1 length and time
1.2 Speed, velocity and acceleration
1.3 Mass and weight
1.4 Density
1.5 Forces
a. Effects of forces
b. Turning effect
c. Conditions for equilibrium
d. Centre of mass
e. Scalars and vectors
1.6 Energy work power
a. Energy
b. Energy resources
c. Work
d. Power
1.7 Pressure
2. Thermal physics
2.1 a. States of matter
b. Molecular model
c. Evaporation
d. Pressure changes
2.2 Thermal properties
a. Thermal expansion of solids, liquids and gases
b. Measurement of temperature
c. Thermal capactiy
d. Melting and boiling
2.3 Transfer of thermal energy
a. Conduction
b. Convection
c. Radiation
d. Consequences of energy transfer
3. Properties of waves, including light and sound
3.1 General wave properties
3.2 Light
a. Reflection of light
b. Refraction of light
c. Thin converging lens
d. Dispersion of light
e. Electromagnetic spectrum
3.3 Sound
4. Electricity and magnetism
, 4.1 Simple phenomena of magnetism
4.2 Electrical quantities
a. Electric charge
b. Current
c. Electro-motive force
d. Potential difference
e. Resistance
f. Electrical energy
4.3 Electric circuits
a. Circuit diagrams
b. Series and parallel circuits
c. Action and use of circuit components
d. Digital electronics
4.4 Dangers of electricity
4.5 Electromagnetic effects
a. Electromagnetic induction
b. a.c. generator
c. Transformer
d. The magnetic effect of a current
e. Force on a current carrying conductor
f. d.c. motor
4.6 Cathode-ray oscilloscopes
a. Cathode rays
b. Simple treatment of cathode-ray oscilloscope
5. Atomic physics
5.1 Radioactivity
a. Detection of radioactivity
b. Characteristics of the three kinds of emission
c. Radioactive decay
d. Half-life
e. Safety precautions
5.2 The nuclear atom
a. Atomic model
b. Nucleus
c. Isotopes
,Units for IGSCE:
quantity unit symbol other units
SI UNITS mass kilogram Kg g
length metre m cm
time second s h, min
area square metre m2 cm2
volume cubic metre m3 cm3
force newton N -
weight newton N -
pressure pascal Pa N/m2
energy joule J kWh
work joule J -
power watt W -
frequency hertz Hz -
PD, EMF volt V -
current ampere A -
resistance ohm Ω -
charge coulomb C -
capacitance farad F -
temperature Kelvin K -
degree Celsius °C
specific heat capacity joules per kilogram ° Celsius J/(kg°C) J/(g°C)
specific latent heat joules per kilogram J/kg J/g
latent heat joule J -
speed metres per second m/s cm/s or km/h
acceleration metres per second per second m/s2
1. General physics
1.1 Length and time
Length:
•A rule (ruler) is used to measure length for distances between 1mm and 1meter; the SI unit for length is the meter (m)
•To find out the volume of a regular object, you can use a mathematical formula, you just need to make a couple of
length measurements.
•To measure the volume of an irregular object you have to put the object into measuring cylinder with water. When
you add the object it displaces the water, making the water level rise. Measure
this rise. This is the volume of your object.
•Micrometers:
Rotate the thimble until the wire is firmly held between the anvil and the spindle.
To take a reading, first look at the main scale. This has a linear scale reading on it. The long lines are every millimetre
the shorter ones denote half a millimetre in between. Then look at the rotating scale. Add the 2 numbers, on the scale
on the right it would be: 2.5mm + 0.46mm = 2.96mm
Time:
•An interval of time is measured using clocks, the SI unit for time is the second(s)
•To find the amount of time it takes a pendulum to make a spin, time ~25 circles and then divide by the same number
as the number of circles.
, 1.2 Speed, velocity and acceleration
• Speed is the distance an object moves in a time frame. It is measured in metres/second (m/s) or kilometres/hour
(km/h).
speed = distance moved / time taken
Distance/time graphs and speed/time graphs:
• Calculating distance travelled:
-with constant speed: speed × time
-with constant acceleration: (final speed + initial speed)/2 × period of acceleration
• Acceleration is the change in velocity per unit of time, measured in metres per second per second, or m/s2 or ms-2.
average acceleration = change in velocity / time taken
a=v-u/s
An increase in speed is a positive acceleration, a decrease in speed is a negative acceleration / deceleration /
retardation.
• If acceleration is not constant, the speed/time graph will be curved.
• The downwards acceleration of an object is caused by gravity. This happens most when an object is in free fall
(falling with nothing holding it up). Objects are slowed down by air resistance. Once air resistance is equal to the force
of gravity, the object has reached terminal velocity. This means that it will stay at a constant velocity. (This varies for
every object). The value of g (gravity) on Earth is 9.81m/s2. However 10m/s2 can be used for most calculations.
Gravity can be measured by using:
Gravity = 2 x height dropped / (time)2
g = 2h / t2
This only works when there is no air resistance, so a vacuum chamber is required.
1.3 Mass and weight
• Mass: the property of an object that is a measure of its inertia (a resistance to accelerate), the amount of matter it
contains, and its influence in a gravitational field.
• Weight is the force of gravity acting on an object, measured in Newtons, and given by the formula:
Weight = mass × acceleration due to gravity
• Weights (and hence masses) may be compared using a balance
1.4 Density
• To determine the density of a liquid place a measuring cylinder on a balance, then fill the measuring cylinder with
some liquid. The change in mass is the mass of the liquid and the volume is shown on the scale, then use the formula:
Density = mass / volume
• To determine the density of an object you use the methods mentioned in section 1.1 to find out volume and then
weigh the object and then use the formula.
1.5 Forces
1.5 (a) Effects of forces
• A force may produce a change in size and shape of a body, give an acceleration or deceleration or a change in
direction depending on the direction of the force.
• Extension/load graph:
By Samuel Lees and Adrian Guillot
1. General physics
1.1 length and time
1.2 Speed, velocity and acceleration
1.3 Mass and weight
1.4 Density
1.5 Forces
a. Effects of forces
b. Turning effect
c. Conditions for equilibrium
d. Centre of mass
e. Scalars and vectors
1.6 Energy work power
a. Energy
b. Energy resources
c. Work
d. Power
1.7 Pressure
2. Thermal physics
2.1 a. States of matter
b. Molecular model
c. Evaporation
d. Pressure changes
2.2 Thermal properties
a. Thermal expansion of solids, liquids and gases
b. Measurement of temperature
c. Thermal capactiy
d. Melting and boiling
2.3 Transfer of thermal energy
a. Conduction
b. Convection
c. Radiation
d. Consequences of energy transfer
3. Properties of waves, including light and sound
3.1 General wave properties
3.2 Light
a. Reflection of light
b. Refraction of light
c. Thin converging lens
d. Dispersion of light
e. Electromagnetic spectrum
3.3 Sound
4. Electricity and magnetism
, 4.1 Simple phenomena of magnetism
4.2 Electrical quantities
a. Electric charge
b. Current
c. Electro-motive force
d. Potential difference
e. Resistance
f. Electrical energy
4.3 Electric circuits
a. Circuit diagrams
b. Series and parallel circuits
c. Action and use of circuit components
d. Digital electronics
4.4 Dangers of electricity
4.5 Electromagnetic effects
a. Electromagnetic induction
b. a.c. generator
c. Transformer
d. The magnetic effect of a current
e. Force on a current carrying conductor
f. d.c. motor
4.6 Cathode-ray oscilloscopes
a. Cathode rays
b. Simple treatment of cathode-ray oscilloscope
5. Atomic physics
5.1 Radioactivity
a. Detection of radioactivity
b. Characteristics of the three kinds of emission
c. Radioactive decay
d. Half-life
e. Safety precautions
5.2 The nuclear atom
a. Atomic model
b. Nucleus
c. Isotopes
,Units for IGSCE:
quantity unit symbol other units
SI UNITS mass kilogram Kg g
length metre m cm
time second s h, min
area square metre m2 cm2
volume cubic metre m3 cm3
force newton N -
weight newton N -
pressure pascal Pa N/m2
energy joule J kWh
work joule J -
power watt W -
frequency hertz Hz -
PD, EMF volt V -
current ampere A -
resistance ohm Ω -
charge coulomb C -
capacitance farad F -
temperature Kelvin K -
degree Celsius °C
specific heat capacity joules per kilogram ° Celsius J/(kg°C) J/(g°C)
specific latent heat joules per kilogram J/kg J/g
latent heat joule J -
speed metres per second m/s cm/s or km/h
acceleration metres per second per second m/s2
1. General physics
1.1 Length and time
Length:
•A rule (ruler) is used to measure length for distances between 1mm and 1meter; the SI unit for length is the meter (m)
•To find out the volume of a regular object, you can use a mathematical formula, you just need to make a couple of
length measurements.
•To measure the volume of an irregular object you have to put the object into measuring cylinder with water. When
you add the object it displaces the water, making the water level rise. Measure
this rise. This is the volume of your object.
•Micrometers:
Rotate the thimble until the wire is firmly held between the anvil and the spindle.
To take a reading, first look at the main scale. This has a linear scale reading on it. The long lines are every millimetre
the shorter ones denote half a millimetre in between. Then look at the rotating scale. Add the 2 numbers, on the scale
on the right it would be: 2.5mm + 0.46mm = 2.96mm
Time:
•An interval of time is measured using clocks, the SI unit for time is the second(s)
•To find the amount of time it takes a pendulum to make a spin, time ~25 circles and then divide by the same number
as the number of circles.
, 1.2 Speed, velocity and acceleration
• Speed is the distance an object moves in a time frame. It is measured in metres/second (m/s) or kilometres/hour
(km/h).
speed = distance moved / time taken
Distance/time graphs and speed/time graphs:
• Calculating distance travelled:
-with constant speed: speed × time
-with constant acceleration: (final speed + initial speed)/2 × period of acceleration
• Acceleration is the change in velocity per unit of time, measured in metres per second per second, or m/s2 or ms-2.
average acceleration = change in velocity / time taken
a=v-u/s
An increase in speed is a positive acceleration, a decrease in speed is a negative acceleration / deceleration /
retardation.
• If acceleration is not constant, the speed/time graph will be curved.
• The downwards acceleration of an object is caused by gravity. This happens most when an object is in free fall
(falling with nothing holding it up). Objects are slowed down by air resistance. Once air resistance is equal to the force
of gravity, the object has reached terminal velocity. This means that it will stay at a constant velocity. (This varies for
every object). The value of g (gravity) on Earth is 9.81m/s2. However 10m/s2 can be used for most calculations.
Gravity can be measured by using:
Gravity = 2 x height dropped / (time)2
g = 2h / t2
This only works when there is no air resistance, so a vacuum chamber is required.
1.3 Mass and weight
• Mass: the property of an object that is a measure of its inertia (a resistance to accelerate), the amount of matter it
contains, and its influence in a gravitational field.
• Weight is the force of gravity acting on an object, measured in Newtons, and given by the formula:
Weight = mass × acceleration due to gravity
• Weights (and hence masses) may be compared using a balance
1.4 Density
• To determine the density of a liquid place a measuring cylinder on a balance, then fill the measuring cylinder with
some liquid. The change in mass is the mass of the liquid and the volume is shown on the scale, then use the formula:
Density = mass / volume
• To determine the density of an object you use the methods mentioned in section 1.1 to find out volume and then
weigh the object and then use the formula.
1.5 Forces
1.5 (a) Effects of forces
• A force may produce a change in size and shape of a body, give an acceleration or deceleration or a change in
direction depending on the direction of the force.
• Extension/load graph:
