Physics Notes
1.
General Physics: i) Length and Time: a) Use of rules and measuring cylinders to find length or volume:
Rulers used to measure distances from millimeters up to a meter
Caliper used if ruler cannot be placed next to object
Tapes used for greater distance
Change in volume in measuring cylinder following addition of object is equal to volume of object b) Micrometer screw gauge:
Revolving barrel with extra scale which opens by one unit each time
Closed at point where object fits in perfectly c) Use of clocks and devices:
Use automatic timings to reduce human error d) Average value for small timings: ii)
Can take reading of values based on large number of occurrence and divide
Example is pendulum time period
Motion: a) Speed:
Distance moved upon time taken b) Velocity and speed difference:
Speed is ignorant of direction, velocity is speed as well as direction of travel c) Acceleration:
Acceleration is equal to change in velocity upon time taken d) Skill based e) Speed from DT graph:
Gradient f) Skill based g) Skill based h) Skill based i) Skill based iii) j) Skill based k) Skill based l) Acceleration for body near Earth:
Constant acceleration
9.8m/s 2 (10)
G = 2h/t 2 m) Effect of air resistance:
With air resistance, lighter objects are slowed down a lot more while falling
Without, different weights fall at the same speed
Mass and weight: a) Mass:
Amount of matter in an object b) Mass as resistance:

iv) v)
Mass resists changes in motion
Greater object offers greater resistance to starting to move, as well as stopping c) Weight:
Force of gravity pulling on/exerted on mass (measured in KG not N) d) Difference between mass and weight (done) e) W = mg f) Weight as effect of gravitational field (done) g) Skill based
Density: a) p = m/v b) Experiment of liquid and regularly shaped solid:
Volume found using measuring cylinder for liquid or formula for solid
Mass found using balance
Mass/volume gives density c) Irregular solid:
Add to liquid and measure change in volume d) Denser object (relative to liquid) sinks, less dense floats
Effects of forces: a) Force:
Push or pull exerted by one object on another
Force may produce change in size or shape of body b) Extension-load graphs:
Greater force caused greater spring extension, greater reading c) Hooke’s Law:
Beneath elastic limit, extension is proportional to load
F = kx (k is spring constant) d) Limit of proportionality:
Point at which material no longer obeys Hooke’s Law and extension is not proportionate e) Force changing motion:
Takes force to get object at rest to move, takes force to change speed or direction
Resistance to change is inertia
Greater mass, greater inertia f) Acceleration (including direction) = Force/Mass g) Skill based h) Circular motion:
To make object follow circular path, inward/centripetal force is needed
Force always acts towards centre of circle
Since object is always changing velocity, it is always accelerating (result of change in direction) i) No resultant force causes rest or constant speed in straight line j) Friction:
Force resisting relative motion of two surfaces

vi)
Leads to heating effect
Can be static (resistance to beginning movement) or dynamic (moving)
Wastes energy (converted to heat energy and lost)
Advantages are giving shoes and tires grip on the ground, and braking systems
Disadvantages are that it prevents machinery from moving freely, and heats up moving parts e) Air resistance is form of friction
Turning effect: a) Moment of force:
Turning effect force
Used in wrench, opening a door, levers b) Increasing force/distance from pivot increased moment c) Moment= product force x perpendicular distance from pivot d) Skill based e) Skill based vii) Conditions for Equilibrium: a) Equilibrium situation:
No resultant force (upward = downward)
No resultant turning effect (clockwise = anticlockwise) b) Experiment:
Balancing a beam viii) Centre of Mass: a) Experiment to find centre of mass of plane lamina:
Make holes in corners
Draw lines straight down
Point where lines meet is centre of mass b) Effect of Position of Centre of Mass on Stability: ix)
If line drawn straight down from centre of mass passes through base, object will not fall
Wider base increases stability
Three types of equilibrium: Stable, Unstable, Neutral
Scalars and Vectors: x) a) Vectors have magnitude and direction, as opposed to just magnitude b) Examples of scalar-vector:
Scalar: Time, volume, speed, temperature, mass, electric charge
Vector: Force, weight, velocity, acceleration, momentum c) Determine result of two vectors:
Parallelogram: Complete parallelogram, diagonal from origin is sum
Triangle: Find two sides touching tales, third side in opposite direction is sum
Can resolve vector into components at right angles
Can use trigonometry to solve
Momentum and Impulse: a) Concepts:
Momentum is tendency of object to keep moving in same direction

xi)
Impulse is measure of how much force changes momentum of an object b) Equation for Momentum:
Momentum = mass x velocity c) Equation for Impulse:
Ft = mv – mu d) Skill based
Energy: a) Identify changes in energy:
Kinetic energy: Energy due to motion, all moving objects have it
Gravitational potential: Energy due to force acting against gravity
Elastic potential energy: Energy due to change in shape, present in stretched rubber band or compressed spring
Chemical potential energy: Energy stored in fuel, batteries, or food
Nuclear potential energy: Energy present due to fore holding together atom
Internal energy: Energy present in all atoms and molecules due to random motion and position b) Equations:
KE = ½ x mv 2
PE = mgh c) Energy is transferred and transformed by various methods:
Forces/mechanical working: Running, moving an object, stretching a spring
Electrical currents: Bulbs, Electrical items
Heating: Splitting an atom
Waves: Energy transferred through electromagnetic, sound, and water waves d) Skill based e) Skill based f) Dissipation of Energy:
Energy spread out among objects and surroundings over events
Greater dissipation, lower efficiency xii) Energy resources:
I.
Obtaining Electricity:
Chemical energy stored in fuel: Fuels are burnt to give heat energy, this turns into heat energy in water, then kinetic energy in turbine, then electrical energy in generator
Water: Kinetic energy from water turns a turbine which turns a generator which produces electrical energy (Tidal energy forms artificial lake through damning estuary and generator is turned through filling and emptying, waves cause up and down movement on surface which can be used to drive generators, hydroelectric is from artificial lake formed behind a dam which turns turbines and then generators when it rushes down)
Geothermal resources: Thermal energy heats water, water turns into steam, thermal energy of steam turns turbine which then has kinetic energy, which turns generator which produces electrical energy

Nuclear energy: Splitting of nuclei releases thermal energy, heats water to steam, turns turbines with kinetic energy and becomes electric in generators
Solar energy: Solar panels absorb energy radiated by sun and use it to heat water for turbines or direct use, solar cells convert light energy into electrical energy
Wind energy: Kinetic energy from wind turns a turbine which turns a generator which produces energy
II.
Sun as source for all energy except geothermal, nuclear, and tide:
Chemical: Sun gives energy to plants, plants convert it into water and carbon dioxide for growth, animals eat plants to get energy, plants and animals die to form fossil fuels through intense pressure, fossils fuels used for energy
Waves: Waves are caused by wind, wind is caused by heated air rising above the equator, heat provided by sun
Hydroelectric: Artificial lakes kept full by river water formed by rain or snow, weather conditions caused by sun
Solar panels and cells: Obvious
Wind: Wind caused by sun
Geothermal: Thermal energy under the Earth’s surface caused by radioactive material, not sun
Nuclear energy: Caused by nuclei of uranium, not sun
Tides: Gravitational pull of mon creates gentle bulges in Earth’s oceans, Earth’s rotation causes high and low tides as they pass in and out of the bulges, motion causes energy, not sun
III.
Sun as nuclear fusion:
Energy of sun released by light nuclei (fusion)
IV.
Advantages and disadvantages of each method:
V.
Method R? Cost Reliability Scal e
Fossil
Fuels
N Low High
Environmental
Impact
High Gives off damaging pollutants
Tidal
Wave
R Initial cost high
R Initial cost high
High as easy to predict tide
Not high, wave size varies
High Affects ecosystem surrounding dam
Not very high
Not damaging
Hydroelectric
R Initial cost high
Very reliable
High Can damage ecosystem, could cause floods
Geothermal
R High Reliable Very high
Not damaging
Other
Affects transport system
Price unstable, limited reservoirs
Difficult to find
D
D
-

Nuclear R Very high
High
Solar R Initial cost high
Lowdepends on weather
Wind R Initial cost
Low- depends high on weather
VI.
Understand efficiency qualitatively:
Very high
Potentially very damaging
High Not damaging
High Not damaging
Many waste products
Need to be large to work
Large area needed, are noisy
Some energy is always transformed into other forms, such as sound or heat
Therefore efficiency is used to see how much of the total power output (input) is in useful form
VII.
Use equation:
Efficiency = useful energy output/energy input or output x 100 xiii) Work: a) Work done = energy transformed or transferred b) Work = Force x Distance Moved xiv) Power: a) Power = Work done (energy transferred)/Time taken xv) Pressure: a) Pressure = Force/Area b) Relate pressure to force and area:
Studs on football boots have small area of contact to put pressure on ground and sink in for extra grip
Area under knife’s blade is very small to put pressure on material and cut
Area under drawing pin is small to put pressure on wood
Skis have large area c) Mercury Barometer:
Device used to measure atmospheric pressure (the weight of air in the atmosphere)
Made of glass, consists of upside down tube, base of tube dips into beaker below surface of Mercury
Atmospheric pressure pushes down the mercury in beaker, which pushes up the mercury in tube
As tube is vacuum, there is no resistance, and atmospheric pressure pushes it up until column of mercury balances pressure (height is used as measure) d) Pressure beneath liquid surface to depth and density:
Pressure acts equally in all directions
Pressure does not depend on shape or width of container
Pressure increases with depth (Deeper into a liquid you go, greater the weight of liquid above and higher the pressure)
Pressure depends on density of liquid (greater density, greater pressure) e) Use equation p = hpg:
To calculate pressure, weight is needed

Mass = density x volume (pAh), weight = pgAh, therefore force on base = Density x Gravity x Height/Area, therefore pressure = Density x Gravity x Height f) Use and describe use of manometer:
One end of manometer is connected to air, one end to gas being measured
If there is pressure difference between ends, mercury column is uneven
2.
Thermal Physics: i) ii)
States of Matter: a) Distinguishing properties of solids, liquids and gases:
Solid has fixed volume, high density, definite shape, and does not flow
Liquid has fixed volume, moderate to high density, no definite shape, and flows
Gas has no fixed volume, low density, no fixed shape, and flows easily
Molecular Model: a) Structure of states of matter:
Solids have particles close together, regular pattern, and vibrate on the spot
Liquids have particles close together, random arrangement, and move around each other
Gases have particles far apart, random arrangement, and move quickly in all directions b) Relate properties to forces and distance between molecules and motion:
Solids have fixed volume due to regular pattern and strong attraction, high density due to close together, definite shape due to same as fixed volume, and do not flow due to regular pattern
Liquids have fixed volume due to close molecules, moderate density due to less close than solids, no definite shape and flowing as they can move past each other
Gases have no shape due to fixed arrangement, low density due to far apart, no fixed volume due to moving around, and flow because moving around iii) c) Interpret temperature of gas in terms of the motion of its molecules:
High temperature, molecules move faster d) Describe pressure of gas in terms of motion of molecules:
High pressure due to faster movement e) Pressure in terms of change in momentum:
Faster movement, more particles striking walls of container, greater pressure f) Random motion of particles in suspension as evidence for kinetic theory:
Smoke (oil droplets) are seen to move randomly
Motion is evidence that air particles (invisible) are also moving randomly and colliding with the smoke droplets
The air particles cannot be seen but their motion can be understood by the smoke droplets which can be seen g) Brownian Motion:
Random motion in various directions
Evaporation:

iv) v) vi) a) Describe evaporation in terms of the escape of more energetic molecules from the surface of the liquid:
All temperatures there is distribution of kinetic energy within liquid
Molecules with highest kinetic energy can escape and become gas b) Subsequent cooling:
Average speed of molecules will decrease when fast ones escape
Temperature of liquid will decrease c) Demonstrate understanding of how temperature, surface area, and draught over a surface influence evaporation:
Temperature: Increases evaporation as more particles have sufficient energy to escape
Draught: Increases evaporation as moving air carries away water molecules
Surface area: Increases evaporation as more molecules are close to the surface d) Explain cooling of object in contact with evaporating liquid:
Evaporation of liquid takes thermal energy away from object too
Pressure changes: a) Effect of volume (at constant temperature) and temperature (at constant volume) on pressure:
As volume decreases, distance between each collision with the wall decreases, molecules collide with wall more often, average force against wall will increase, pressure will increase
As temperature increases, kinetic energy of molecules increases, speed increase, strike walls with more force, pressure increase b) Recall and use equation:
P1V1 = P2V2
Thermal expansion: a) Thermal expansion of solids, liquids, and gases and constant pressure:
Solids and liquids made up of tiny vibrating particles which attract each other
Higher temperature, faster vibration
Vibrations take up more space, object expands in all directions
Gas will collide with container with more force and regularity, if container dimensions are free to change it will expand b) Everyday applications of thermal expansion:
Solid: Railway lines given space to expand at end of line, jam jar lids are heated if they are not opening, overhead cables given slack to allow for contraction, thermostat has bimetal strip that bends when heated too much (bends towards one which expands less)
Liquid: Thermometers have liquids that expand on heating
Gases: Car tires pressure will increase as they become hot while driving, convection currents c) Difference between solids, liquids, and gases:
Different levels of freedom, different kinds of expansion
Measurement of Temperature: a) Physics properties used for measurement:

Volume: Increases with temperature: used for Mercury in glass thermometer
Resistance: Increases with temperature: used for Resistance thermometer
Current: Increases with difference: used for Thermocouple thermometer
Current: Increases with temperature: used for Thermistor thermometer b) Recognise the need for and identify fixed points:
Used to calibrate thermometers
Boiling and melting water can be used as these 2 changes occur at fixed temperatures
The thermometer can be placed in boiling and melting water to make marks c) Describe structure and action of liquid-in-glass thermometers:
As temperature rises, liquid expands
At any temperature liquid will have fixed volume d) Demonstrate understanding of sensitivity, range, and linearity:
Sensitive thermometers have threads of liquid that move further for rise in temperature, sensitivity increased by narrower tube, more expanding liquid
Range is difference between highest and lowest point on thermometer, increased by using liquid with greater gap between melting and boiling point
Linearity: Within range, expansion is uniform e) Describe structure of thermocouple:
Consists of two metals
When one junction between two metal types is higher than other voltage is produced
Voltage is dependent on temperature difference between junctions
They have a large range and can record temperature very quickly vii) Thermal capacity:
I.
Relate a rise in temperature to increase in internal energy:
Internal energy = random kinetic energy + potential energy of particles
If temperature rises, kinetic energy has increased
Rise in kinetic energy causes rise in internal energy
II.
Simple molecular account:
Higher temperature, molecules have more kinetic energy, internal energy increased
III.
Show an understanding of the term thermal capacity:
Energy required to raise temperature by 1K
IV.
Use equation:
Thermal capacity: Change in energy/change in temperature
Specific heat capacity x mass
V.
Define specific heat capacity:
Energy required to raise a unit mass of a substance by 1K
VI.
Use equation:
Change in temperature/ mass x change in temperature
Energy transferred = Mass x specific heat capacity x change in temperature
VII.
Describe experiment:
Measure temperature of material before and after heating

Measure energy input from heating by measuring voltage, current, and time
Insulate object to avoid losing energy viii) Melting and boiling:
I.
Describe as no change in temperature:
Melting and boiling are changes in state, wherein the energy input does not reflect in a change in temperature
II.
State meaning of melting and boiling point:
Melting point: Temperature at which solid and liquid phases exist in equilibrium
Boiling point: Temperature at which substance changes from a liquid to a gas throughout the bulk of a liquid
III.
Condensation and solidification:
Condensation: Kinetic energy of particles falls, attractive forces slowly pulls them back into droplets, bonds are formed
Solidification: Kinetic energy of particles decreases, permanent bonds are formed, no longer able to move freely
IV.
Distinguish between boiling and evaporation:
Boiling happens only at fixed point, evaporation is at all temperatures ix)
Boiling happens throughout the liquid, evaporation is only at surface
Boiling affects all particles, evaporation only the particles with sufficient kinetic energy
Boiling keeps same temperature of liquid, evaporation decreases
V.
Latent heat of vaporisation and fusion:
Vaporisation: Energy change associated with a substance boiling or condensing
Fusion: Energy change associated with a substance melting or solidifying
Molecular interpretation: Transition bonds are being broken or formed, this gives an associated intake or release of energy
VI.
Define specific latent heat:
Amount of energy per mass unit absorbed or released during a change of phase
VII.
Describe experiment:
Take volume of liquid to its boiling point
Measure mass
Boil water for fixed period and calculate energy input through voltage, current, and time
Record mass of liquid after heating and calculate mass turned into gas
L = Current x time x voltage / Mass 1 – Mass 2
Heat ice until it starts to melt
Capture melted ice in the beaker on the balance
Heat for fixed length of time and calculate energy input by measuring the voltage and current supplied by heater
Measure mass of water melted during that period
L = Current x time x voltage / Mass of Water melted
VIII.
Equation:
Energy transferred = mass x specific latent heat
Conduction:

x) xi) a) Describe experiments to demonstrate properties of good or bad conductors of heat:
Wax and coin are attached to object to be tested
Other end of object heated
Ability of object to conduct heat can be judged by how quickly wax melts and coins are released
Rods coated with thin layer of wax can be connected to boiling tank
Length of melted wax shows which material is best conductor b) Give a simple molecular account of heat transfer in solids:
When a material is heated, particles move faster, push on neighboring particles, and speed up those too
All materials conduct like this, but metals have free electrons in lattice which speed up when heated and collide with atoms to speed them up
Thermal energy is rapidly transferred to all parts c) Insulation examples:
Plastic foam lagging around hot water tank to prevent heat loss
Glass or mineral wool insulation in loft to keep house cool
Wall cavity filled with plastic foam, beads, or mineral wool
Double glazed windows with two sheets of air between them
Convection: a) Recognise convection as important method of thermal transfer in fluids b) Relate convection to density changes and describe experiments:
Hot water expands and becomes less dense, rises upwards and cooler, denser water sinks and displaces it
Where water is heated, its particles gain energy and vibrate more rapidly
As particles circulate, they transfer energy to other parts of beaker
Heat water with potassium permanganate crystals to colour c) Convection examples:
Beaches, land heats up more quickly than sea, warm air rises above land, is displaced by cooler air from sea, night sea stays warmer, land cools down quickly, warmer air rises above sea, is displaced by cooler air moving out from land
Hot water system has cold water in storage tank which sinks down to boiler, is heated, heated water rises to top and collects in storage tank which is insulated
Room heating has heater at bottom to create convection current
Fridge has freezer at the top
Radiation: a) Identify infra-red radiation as part of electromagnetic spectrum:
Sun’s energy travels in form of invisible infrared waves as well as light
Can travel through a vacuum
Heat up things that absorb them b) Recognise that thermal energy by radiation does not require medium:
Infrared and light rays are electromagnetic
Do not need medium to propagate c) Describe the effect of surface colour and texture on emission, absorption, and reflection of radiation:

Emitters: Black best to white worst, dull best to shiny worst
Reflectors: Black worst to white best, dull worst to shiny best
Absorbers: Black best to white worst, dull best to shiny worst d) Describe experiments to show properties of emitters and absorbers:
Emitters: Metal cube with matt black and shiny white faces filled with boiling water, thermal radiation detector placed at same distance from both, meter readings compared
Absorbers: Matt black and shiny white plates placed at same distance from radiant heater, thermometer placed behind both to measure rises in temperature e) Amount of radiation emitted depends on surface temperature and surface area of body:
Greater surface temperature, greater emission
Greater surface area, greater emission f) Vacuum flask:
Insulated stopper to reduce conduction and convection
Double-walled container with gap between walls, air removed to reduce conduction and convection
Walls have silvery surfaces to reduce thermal radiation and reflect xii) Consequences of Energy Transfer: a) Identify application:
Conduction: Saucepan or wok: Made of copper or other good conductors
Convection: Air conditioner: Normally placed on ceiling
Radiation: Paint: Hot climate houses are painted white
3.
Properties of Waves:
I.
General Wave Properties: a) Demonstrate understanding that waves transfer energy without transferring matter:
Example is swing
When someone is pushed, the mass of pusher stays where it is
Kinetic energy just has to be transferred b) Wave motion in ropes and springs and experiments using water waves:
Particles in rope vibrate in fixed positon and energy in particles are transferred from one end of rope to other end
Wave travels as a “sideway pulse”
Water waves ensure that an object that is floating experiences and up and down motion
Waves carry energy without the net movement of particles c) Use the term wavefront:
Lines connecting points with the same phrase on propagation d) Meaning of speed, frequency, wavelength and amplitude:
Amplitude: A: Maximum displacement from mean position (meter)
Frequency: f: The number of oscillations that take place in 1 second (Hertz)
Wavelength:
 
Shortest distance between two points in phase with one another (meter)

II.
Wave speed: v: The speed at which wave fronts pass a stationary observer
(relative to speed of light) e) Recall and use equation:
Velocity (m/s) = frequency (Hz) v wavelength (m) f) Distinguish between two types of wave and give examples:
Transverse: Oscillation is perpendicular to direction of energy propagation: seismic S waves, all electromagnetic waves
Longitudinal: Oscillation is perpendicular to direction of energy transfer: Seismic
P waves, sound waves: form compressions and rarefactions (bunched up and stretched out) g) Describe how waves can undergo:
Reflection at plane surface: Waves are reflected from surface at same angle as they strike it (presuming surface is smooth)
Refraction: If a surface allows waves to pass through, the speed of wave change due to different density. As frequency is unchanged, a decrease in speed causes a decrease in wavelength, and wavefronts gap changing causes change in direction of travel
Diffraction: Waves bend round side of obstacle or spread out as they pass through a gap h) Effect of wavelength and gap on diffraction:
Diffraction only significant if the size of the gap is about the same as the wavelength
Wider gaps produce less diffraction i) How wavelength affects diffraction at an edge:
Long wavelength causes greater diffraction in waves
This is why television waves are more difficult to receive in hilly areas than radio waves which have a longer wavelength and why the diffraction of light is so difficult to observe j) Use of water waves to observe processes:
Put water in tank and use motor to produce vibrations
Place vibrating block to produce ripples
Vertical surfaces put in path for reflection
Flat piece of plastic makes water more shallow and slows wave for refraction
Obstacle being placed shows ripple bending around it for diffraction
Reflection of Light: a) Describe formation and characteristics of optical image by plane mirror:
After reflection, some rays enter eye
These rays appear to come from position behind mirror where image is seen
Image is: virtual, upright, same size, laterally inverted, same distance as mirror from object b) Image is virtual:
Rays do not actually meet behind mirror
Therefore image is not real c) Recall and use law:

III.
Angle of incidence = angle of reflection d) Perform simple constructions, measurements, and calculations:
Refraction of Light: a) Experimental demonstration:
Put stick in water
Stick appears closer to surface of water
Virtual image b) Use terminology to describe passage of light:
Light enters medium with higher density
Lights slows down and changes path
Light ray then emerges parallel to original direction (provided object has parallel sides)
Refraction will occur if glass were replaced with another transparent material c) Give the meaning of critical angle:
The angle of incidence beyond which light will totally internally reflect d) Describe internal and total internal reflection:
Less than critical angle, ray splits into a refracted ray and weaker reflected ray
At critical angle, refracted only just leaves the surface
Beyond critical angle, ray is totally internally reflected perfectly e) Use definition of refractive index n in terms of speed:
Refractive index is measure of the change in speed, carried out by comparing it to the speed of light
Medium with highest refractive index slows light down the most, and has the greatest bending effect f) Use equation:
n = sin i/sin r g) Use equation 2:
n = 1/sin c
This is because angle of incidence = 90 (1) if drawing reversed e) Use of optical fibres:
Thin, strands of glass that can carry digital signals in the form of pulses of light
At transmitting end, electrical signals are encoded into light signals by LED
Photodiode turns them back into electrical signals
Used to carry long-distance transmission in telephone networks
Used in high speed communications, such as television and broadband
Endoscopes used in body to give doctors clear image of inside
IV.
Thin converging lens: a) Describe action:
Thin converging lens bend beam of light and form images b) Principle focus and focal length:
The point where rays parallel to principal axis meet is called principal focus
Distance between centre of lens and principal focus is focal length c) Ray diagrams d) Ray diagrams

e) Use of single lens as magnifying glass:
As object is moved towards lens, image becomes bigger and further away
If it is between lens and F, rays do not meet and image appears to come from behind lens
Virtual image formed, cannot be picked up, works like magnifying glass f) Describe image:
Enlarged/same size/diminished
Upright/inverted g) Understanding of real and virtual image:
Real image has rays that actually meet and can be picked up on a screen
V.
Virtual image doesn’t have rays that meet and cannot be picked up
Dispersion of light: a) Qualitative account of splitting of light:
Sides of prism are not parallel, so light comes out in different direction
(deviated)
White light passed through prism splits into a range of colours called a spectrum
Effect is called dispersion
Occurs because different colours are each refracted by different account
Greatest wavelength refracted the least
Therefore, order: ROYGBIV b) Light of single frequency is monochromatic
VI.
Electromagnetic Spectrum: a) Main features of electromagnetic spectrum in order of wavelength:
Highest frequency and lowest wavelength to lowest frequency and highest wavelength: Gamma rays, X-Rays, UV, VIBGYOR, Infrared, Radio waves
(Microwaves-UHF-VHF-short wave-medium wave-long wave)
Rudolph is really underutilizing xylophone gifts b) Speed of electromagnetic wave in vacuum:
3 x 10^8 c) All waves travel at same high speed in vacuum d) Describe typical properties and uses of radiation:
Radio and TV communications (Radio waves): Radio waves are used to transmit
TV pictures, will bend around hills due to high wavelength
Satellite television and telephones (microwaves): Used by mobile phones, for beaming TV and telephone signals, produce heating effect when absorbed
Electrical appliances, remote controllers, and intruder alarms (infrared): Security alarms switched by motion sensors that pick up changing pattern of infrared, all objects emit some infrared because of motion of their atoms or molecules, hotter objects emit more infrared
Medicine and security (X-Rays): X-rays given off when fast-moving electrons lose energy very quickly, long-wave rays are not very penetrating, can be used to take photographs that reveal flaws inside metals or body, but damage living cells deep inside body e) Describe awareness of safety issues regarding the use of microwaves and X-rays:

Microwaves cause internal heating of body tissues, which is dangerous
X-rays can damage living cells deep inside body, and can cause cancer or
VII.
Sound: mutations a) Production of sound by vibrating sources:
Vibrating objects cause compression and rarefactions in the air around them, which travel to our ears through solids, liquids, and gases b) Describe longitudinal nature of sound waves:
Air oscillates backwards and forwards as compressions and rarefactions pass through it
Compression passes, air pressure rises
Rarefaction passes, air pressure falls
Distance from compression to compression is wavelength c) Describe compression and rarefaction:
Compression is area where particles are bunched up
Rarefaction is area where particles are stretched-out d) State human range:
20 Hz-20,000 Hz e) Ultrasound:
Sounds above range of human hearing f) Medium: S
Sound waves are mechanical
Medium is needed for transmission g) Describe experiment to show speed of sound:
Known distance from wall, time for echo to return h) Typical values of speed of sound:
Gases: 330 m/s in dry air at 0, 350 m/s in dry air at 30 degrees
Water (pure): 1400 m/s
Concrete: 5000 m/s i) Relate loudness and pitch to amplitude and frequency:
Amplitude: Higher amplitude- greater displacement- greater volume
Frequency: Higher frequency- more oscillations- higher pitch j) Reflection of sound causes echo:
4.
Electricity and magnetism:
I.
Simple phenomena of magnetism: a) Describe forces between magnets and between magnets and magnetic materials:
Magnetic forces seem to come from poles at the end of the magnet
Two poles: North seeking pole (North Pole) and South seeking pole (South Pole)
Like poles repel and unlike poles attract
Magnetic materials are attracted to magnets b) Magnetic forces causes:

Magnetic forces between two bodies exist due to interaction between magnetic fields
Electrons have slight magnetic effect when the spin and orbit nucleus
In magnetic material, atomic c) Induced magnetism:
Magnetic materials are attracted to magnets because they become magnetized in the presence of a magnet
The magnet induces magnetism in them, with the pole nearest to the magnet induced opposite to the pole at the end of the magnet
Attraction between unlike poles holds material to magnet d) Magnetic and non-magnetic materials:
Magnetic: Can be magnetized and is attracted to magnets (Iron, nickel, cobalt)
Non-magnetic: Cannot be magnetized and is not attracted to magnets (Brass, copper, zinc, tin, aluminium, non-metals) e) Describe methods of magnetization:
Stroking: Magnet is stroked across material
Use of DC in coil: Put in a coil of wire and high DC is passed through wire
Hammering in magnetic field: Material placed in magnetic field and hammered f) Describe methods of de-magnetization:
Heating: All magnets have temperature at which they lose their magnetism
Use of AC in coil: Object is magnetized in opposite direction each time current reverses, but amount of magnetism is reduced each time
Hammering: Throws atomic magnets out of line g) Draw pattern of magnetic field lines around bar magnet:
Lines heading from N to S of magnet in circular form
Size of circles increases as you move closer to edge h) Describe experiment to find pattern of magnetic field lines including direction:
Compass held near one end of magnet
Needle position is marked using two dots
Compass moved so that needle lines up with previous dot and so on
When dots are joined, magnetic field lines is formed
Magnetic field is strongest where lines are closest together
Compass will point towards S pole i) Distinguish between properties of soft iron and steel:
Soft iron: Soft magnetic material: magnetism is temporary
Steel: Hard magnetic material: magnetism is permanent j) Distinguish between design and use of permanent magnets and electromagnets:
Permanent: Hard magnetic material: For application when magnetism is needed over longer periods (fridge doors)
Electromagnets: Use a solenoid to create magnetic field: For application where
II.
magnetic field needs to be turned on and off: Relay, circuit breakers, storage
Electric Charge: a) State that there are positive and negative charges b) State that like charges repel and unlike charges attract

c) State that charges are measured in coulombs d) Describe simple experiments to show production and detection of electric charge:
Perspex rod rubbed with cloth (positive) will attract polythene rod rubbed with cloth (negative)
Charged rode will induce opposite charges in sphere which can then be earthed
Golf leaf electroscope: If charged object is placed near cap- Charges are induced in electroscope- other charges are repelled down to leaf- gold leaf diverges e) State that the direction of an electric field at a point is the direction of the force on a positive charge at that point f) Describe an electric field:
A region in which an electric charge feels a force g) State that charging a body requires removal or addition of electrons h) Describe simple field patterns:
Point charge: Away from positive, towards negative
Charged conducting sphere: Charges collect at edge as they repel each other, away from positive and towards negative, strongest at sharpest curve
Parallel plates: Straight lines from positive to negative, slight curves towards edge i) Give an account of charging by induction:
If charged object is held above uncharged object, charges opposite to charged object collect near it
One side of object has more electrons than normal, one has fewer
If one side is earthed, overall object ends up with charge j) Distinguish between conductors and insulators and give examples:
Conductors: Materials that let electrons pass through them, electrons are loosely held to their atoms, good thermal conductors as well (metals)
Insulators: Hardly conduct at all, electrons tightly held to atom, can be transferred by rubbing, easy to charge as electrons that get transferred tend to stay where they are (non-metals except graphite) h) Use electron model to distinguish between conductors and insulators:
In conductor, charges are free to move between atoms
In insulator, charges are not free to move between atoms
III.
Current: a) State that current is related to flow of charge b) Show understanding that current is a rate of flow of charge and use formula (Current =
Charge/Time) c) Use and describe use of ammeter:
Measures the current flowing in amperes (A)
Always placed in series to component of which current is being measured d) State that current in metal is due to flow of electrons e) Distinguish between electron flow and conventional current:
Conventional current direction is taken from + to – around the circuit
Electrons flow from – to + due to force of repulsion
CCD defined before electron was discovered

Mathematically, transfer of positive charge is same as transfer of negative charge in opposite direction
IV.
Electromotive Force: a) State the EMF is electrical source of energy measured in volts b) Understand EMF definition:
Defined in terms of energy supplied by a source in driving charge around a complete circuit
EMF: Total energy difference per unit charge around a circuit
Is the voltage (potential) that a battery will supply
Is the work done per unit of charge by the cell in driving charge around the
V.
complete circuit
Potential Difference: a) State the potential difference across a circuit component is measured in volts
Measure of how many joules per coulomb (volts) there are in a specific point of a circuit
Potential energy represents how much energy is there to drive a current through the wire and is measured in volts
Potential difference is the difference in potential between two pints of a circuit
PD across a component is the work done per unit of charge in driving charge through the component b) Recall that `1V = 1 J/C c) Use and describe of a voltmeter:
Voltmeter measures potential difference across a component
Always connected in parallel to component
VI.
Resistance: a) State that resistance = PD / current and understand qualitatively how changes in PD or resistance affect current:
If material obeys Ohm’s Law, current will increase in proportion to potential difference increase (at constant resistance)
If material obeys Ohm’s Law, current will be inversely proportionate to current
(at constant voltage) b) Recall and use equation R = V/I c) Describe experiment to determine resistance using voltmeter and an ammeter:
Voltmeter in parallel, ammeter in series d) Sketch and explain the current-voltage in:
Ohmic resistor: Straight line passing through 0, 0
Filament lamp: Curved because as current increases, heats up and resistance increases and current stops increasing proportionately e) Effect of length and cross-sectional area on resistance:
Increasing length = increasing resistance
Increasing cross-sectional area = decreasing resistance
R = (pL/A)
R x A / L = R1 x A2 / L2
VII.
Electrical energy:

a) Understand energy transfer:
Circuits transfer energy from battery/power source into components
Some is also radiated out to surroundings b) Recall and use equations:
Power (W) = Voltage x Current
Energy (J) = Power (VI) x Time
VIII.
Diagrams: a) Draw and interpret circuit diagrams containing sources, switches, resistors (fixed and variable), heaters, thermistors, light-dependent resistors, lamps, ammeters, voltmeters, galvanometers, magnetising coils, transformers, bells, fuses and relays (skill based) b) Draw and interpret diagrams containing diodes
IX.
Series and parallel circuits: a) Understand that current at every point in series circuit is same b) Calculate the combined EMF of several sources in series
Add up EMF of each source c) Give the combined resistance of two or more resistors in series
Add up resistance of each component d) Recall and use fact that adding up PDs of each component is equal to PD across supply e) State that for parallel circuit, current from source is larger than current from each branch f) Recall and use fact that current from source is equal to sum of currents from each branch in a parallel circuit g) Calculate effective resistance of two or more resistors in parallel
1/R(total) = 1/R1 + 1/R2 h) State the advantage of connecting lamps in parallel:
Circuit does not stop working if one goes off
Can be turned on and off individually
Each bulb glows brightly
X.
Action and use of circuit components: a) Variable potential divider (potentiometer):
Resistor or series of resistors used to vary output voltage
Changing the position of potentiometer varies voltage
Voltage dropped across that section of the resistor will vary b) Describe the action of a diode and show understanding of its use as a rectifier:
Diode allows current only to flow in one direction only
Four diodes used to convert AC current to DC c) Describe the action of thermistors and light dependent resistors and show understanding of their use as input transducers:
Transducers: Devices that convert one type of energy into another
Thermistor: Higher temperature, lower resistance, higher PD across fixed resistor (in series) and higher current (in parallel)
LDR: Increasing light intensity, lower resistance, higher PD across fixed resistor
(in series) and higher current (in parallel) d) Recognise and show understanding of light-sensitive switches and temperature-operated alarms:

LDR’s can be used in light-sensitive switches coupled with relay
-
Increase of temperature causes current to flow, activating electromagnetic switch that operates alarm e) Relay:
Electromagnetic switch, activated when current is passed through it
When current pulls one switch contact towards or away from each other, can be used to turn on second circuits
XI.
Dangers of Electricity: a) State the hazards of:
Damaged insulation: Risk of electrocution when handling wires
Overheating of cables: Insulation will melt and wires become exposed
Damp conditions: Impure water conducts electricity so risk of electrocution b) State that a fuse protects a circuit c) Explain the use of fuses and circuit breakers and choose appropriate fuse ratings and circuitbreaker settings:
Fuse: Thin piece of wire which melts and breaks if too much current passes through it- used to cut circuit if current is too high
Circuit breaker: Automatic electrical switch which will cut a circuit if the current is too high- electromagnet arranged to pull bolt away and release switch, turning off circuit
Should be set just above optimal current
Most common ratings 3A, 5A, 13A d) Explain the benefits of earthing metal cases:
Safety wire that connects metal body of the kettle to earth and stops it becoming live- if something goes wrong inside the appliance and the live wire touches the metal case, it could cause harm when touched- but earth wire creates safe route for current to move away- has low resistance, and therefore breaks fuse
XII.
Electromagnetic induction: a) Show understanding that a conductor moving across a magnetic field or a changing magnetic field linking with a conductor can induce an EMF in the conductor:
When conductor cuts magnetic field (wire or magnetic could be moving),
EMF/current is induced in the wire
If wire forms part of complete circuit, EMF makes current flow b) Direction of induced EMF (and so current) oppose the change causing it:
Makes magnetic field opposite to field of the magnet
If N Pole of magnet moved towards solenoid, solenoid will have N pole to repel it c) Factors affecting magnitude of Induced EMF:
EMF induced in conductor is proportional to rate at which magnetic field lines are cut by the conductor
Moving wire faster
Using a stronger magnet

Increasing length of wire in magnetic field d) Reversing direction of induced EMF:
Moving wire in opposite direction
Turning magnets around to reverse field e) State and use relative directions of force, field, and current:
Hold fingers of right hand parallel to each other
Thumb is force (direction of motion), first finger is field, second finger gives current f) State experiment to demonstrate electromagnetic induction:
Connect solenoid to galvanometer with centre-zero
Move magnet towards solenoid
Check for deflection
XIII.
AC Generator: a) Distinguish between DC and AC:
DC: Electric charge only flows in one direction
AC: Electric charge changes direction periodically b) Describe and explain rotating coil generator and use of slip rings:
AC generator used to provide current
Coil placed in magnetic field and rotated by turning shaft
Slip rings fixed to coil and rotate with it
Brushes are two contacts made of carbon which rub against slip rings and keep coil connected to the outside part of the circuit
When coil is rotated, cuts magnetic field, so EMF is generated
Increase EMF by: Increasing number of turns on the coil, increasing area of the coil, using stronger magnet, rotating coil faster c) Sketch graph of voltage output against time d) Relate the position of coil to voltage output:
When normal to coil is perpendicular to field lines, output is maximum
When normal is parallel, output is zero
Therefore when coil is horizontal, output is maximum
When coil is vertical, output is zero
XIV.
Transformer: a) Describe construction of basic iron-cored transformer as used for voltage transformations:
Primary coil placed next to AC input voltage, secondary coil next to output
Connected with core made of soft magnet (iron or Mumetal) b) Describe principal of operation for transformer:
When alternating current flows through input coil, sets up an alternating magnetic field in the core and therefore in the output coil
This changing field induces an alternating voltage in the output coil c) Recall and use equation:
V2/V1 = n2/n1 (n=Number of coils) d) Recall and use equation:
V
1
I
1
= V
2
I
2
(for 100% efficiency, no power lost) e) Understand terms step-up and step-down:

Step up: Output coils and voltage higher
Step down: Input coils and voltage higher f) Describe use of transformers in high voltage transmission of electricity:
Output of a power station is high current
Transformer converts to low current and high voltage before passing through overhead cables
Second transformer use to lower voltage before the supply enters homes g) Advantage of high voltage-transmission:
Energy lost = I 2 R
High current = Higher power loss
Low current = lower power loss
Thinner, lighter, and cheaper cables can be used due to low current as well
XV.
Magnetic effect of current: a) Describe pattern of magnetic field due to currents in straight wires and in solenoids:
Wire: Hold wire in right hand with thumb in direction of current, fingers give you magnetic field direction pointing to S pole
Solenoid: Hold solenoid in right hand with fingers curling in direction of current, thumb gives direction of magnetic field b) State the qualitative variation of strength of magnetic field over salient parts of pattern:
When field lines are closer together, field is stronger
Direction of arrow shows where compass would point (N to S) c) Describe applications of magnetic effect, including relay:
Circuit breakers: Current flows through two contacts, as well as electromagnet- when current gets too high, electromagnet pulls strongly enough to break the contact and release the iron catch- contacts open and current stops
Magnetic relay: Switch operated by electromagnet- small switch with thin wires can be used to turn on current in much more powerful circuit- current in electromagnet causes iron armature to be pulled towards it- contact closes- current flows through larger circuit d) State that the direction of the magnetic field line at any point is the direction of the force on the
N pole of the magnet at that point e) Describe the effect on the magnetic field of changing magnitude and direction of current:
XVI.
Force on current carrying conductor: a) Describe an experiment to show that a force acts on a current-carrying conductor in a magnetic field:
Current reverses: field reverses
Current increases: strength of field reverses
Place wire in magnetic field and turn on power, wire moves a tiny bit
If current is reversed, direction of force will be reversed
If magnetic field is reversed, direction of force will be reversed b) State relative directions of force, field, and current:
Hold fingers of left hand perpendicular to each other
First finger in direction of field
Second in direction of current

Thumb gives direction of force c) Describe an experiment to show the corresponding force on beams of charged particles:
Electron is opposite to current, so effect will be opposite to left hand rule
Proton will be in same direction as current
XVII.
DC Motor: a) State that a current-carrying coil in a magnetic field experiences a turning effect and that the effect is increased by:
Increasing the number of turns on the coil
Increasing the current
Increasing the strength of the magnetic field b) Relate this to the action of an electric motor:
Current is passed through a coil
Experiences a force
Coil feels a force which rotates the coil
Commutator is attached to motor to ensure that current direction reverses periodically
Without commutator, coil would turn back in previous direction
Carbon brushes used to keep a constant flow of electricity
5.
Atomic Physics:
I.
Atomic Model: a) Describe structure of atom:
Nucleus consists of protons and neutrons- net charge positive
Held in nucleus by nuclear force
Electrons orbit nucleus at high speed
Electrons carry negative charge, held in orbit by force of attraction from protons
Net charge zero as number is equal b) Describe how the scattering of α-particles by thin metal foils provides evidence for the nuclear atom:
Metal foil placed in path of beam of alpha particles from source
Some passed straight through gold atoms, some were repelled so strongly that they bounced back or were deflected through large angles
Therefore atom is mostly empty space and mass in concentrated in centre
(nucleus)
II.
Nucleus: a) Describe composition of nucleus:
Protons and neutrons
Called nucleons b) State charges:
Protons: +1
Neutrons: 0 c) Use term proton number:
Number of protons in atom d) Use term nucleon number:

Number of protons and neutrons = mass e) State meaning of nuclear fission and fusion:
Fission: Reaction where heavy nucleus splits spontaneously or due to impact with another particle to release energy
Fusion: Nuclei with low atomic number fuse to form heavier nucleus, with release of energy f) Use the term nuclide and use notation A
Z
X
Nuclide: An atom characterized by distinct number of neutrons and protons g) Balance equations involving nuclide notation: h) Use and explain term isotope:
Isotopes are atoms of same element with different number of neutrons
Physical properties vary, chemical are the same
III.
Detection of radioactivity: a) Background radiation:
Small amount of radiation around at all times due to radioactive materials in environment
Comes from natural sources such as rocks, soil, air, or even foods and building materials
Radon gas is problem when it collects in house b) Detecting radiation:
Window at end is thin enough for particles to pass through
Radiations enters tube, ionizes argon gas
This sets up high voltage spark across gas and causes pulse of current in circuit
Current is amplified and detected on counter
Tube can be connected to: Ratemeter, Scaler, Amplifier/Loudspeaker
Reading must be made first without particles to eliminate background radiation
IV.
Characteristics of types of emissions: a) Discuss random nature of emissions:
Radioactive emission occurs randomly over space and time
Cannot predict which nucleus will decay and when b) Identify alpha, beta, and gamma by:
Nature: Alpha (Helium Nuclei, 2 P + 2 N), Beta (1e-), Gamma (electromagnetic ways similar to X-rays)
Mass: Alpha high, beta low, gamma no mass
Speed: Alpha (up to 0.1 x SOL), Beta (up to 0.9 x SOL), Gamma (SOL)
Ionising power: Alpha (Strong), Beta (Weak), Gamma (Very weak)
Penetrating effect: Alpha (Not very penetrating, stopped by thick sheet of paper of few centimetres of air), Beta (Stopped by few metres of aluminium), Gamma
(Very penetrating, never completely stopped, intensity can be reduced by lead or thick concrete wall) c) Describe deflection:
Alpha: Deflected towards negative parallel to electric field, deflected slightly perpendicular to magnetic field according to left-hand rule

Beta: Deflected towards positive parallel to field, deflected heavily perpendicular to field with opposite of left hand rule
Gamma: Not deflected in either field d) Give examples of practical use:
Tracers in medicine: Gamma emitter drunk, detector measures activity of tracer to see how quickly it becomes concentrated (Iodine 123)
Tracers in industry: Leaks can be detected by adding tracer to fluid
Sterilisation of food and surgical instruments: Exposure to high dose of gamma
V.
rays can kill al microbes so food is kept fresher and instruments are clean
Carbon dating: Amount of Carbon-14 remaining says how old object is
Thickness control
Radiotherapy: Killing cancer cells with high doses of gamma rays
Energy generation
Radioactive Decay: a) State meaning of decay:
Emission of alpha or beta particles alters number of protons or neutrons
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