O Level Exam Skills Hub

Learning objectives

• Represent a physical quantity with a numerical magnitude and unit
• Recall the six prescribed SI base quantities and their units
• Use the prescribed SI prefixes from nano to tera
• Compare orders of magnitude from a typical atom to the Earth
• Select and justify measuring instruments by range and precision
• Distinguish scalar and vector quantities and give examples
• Add two vectors graphically to determine a resultant
• State what speed means
• State what velocity means, including its direction
• Calculate average speed from total distance and total time
• Calculate acceleration as change in velocity divided by time taken
• State what uniform acceleration means
• Interpret examples of non-uniform acceleration
• Plot and interpret displacement–time and velocity–time graphs in one dimension
• Deduce rest and uniform or non-uniform velocity from a displacement–time graph
• Deduce rest, uniform velocity and uniform or non-uniform acceleration from a velocity–time graph
• Use signed area under a velocity–time graph to determine displacement
• Recall constant free-fall acceleration near Earth as approximately 10 m/s²
• Distinguish contact forces from non-contact forces
• State that mass measures the amount of matter in a body
• Describe a gravitational field as a region where a mass experiences gravitational force
• Define gravitational field strength as gravitational force per unit mass
• Apply weight = mass × gravitational field strength
• Distinguish mass from weight
• Describe the effect of balanced and unbalanced forces on a body
• Describe ways a force may change motion
• Identify action–reaction pairs on interacting bodies
• Draw free-body diagrams for force systems in at most two dimensions
• Solve three-force static equilibrium graphically
• Apply resultant force = mass × acceleration
• Relate mass to resistance to change in motion
• Explain the effects of friction on motion
• Describe falling with and without air resistance, including terminal velocity
• Describe a moment as a force's turning effect in everyday examples
• Apply moment = force × perpendicular distance from the pivot
• State the principle of moments for a body in equilibrium
• apply the principle of moments to new situations or to solve related problems
• show an understanding that the weight of a body may be taken as acting at a single point known as its centre of gravity
• Explain qualitatively how centre-of-gravity position affects stability
• Define pressure as force per unit area
• Apply pressure = force ÷ area
• Explain pressure transmission in a hydraulic press
• Apply density = mass ÷ volume
• Apply liquid-column pressure = height × density × gravitational field strength
• Explain how liquid-column height measures atmospheric pressure
• Explain how a manometer measures pressure difference
• Recognise kinetic, potential, nuclear and internal energy stores
• Describe mechanical energy transfer by a force acting over a distance
• Describe electrical energy transfer by an electric current
• Describe energy transfer by heating due to a temperature difference
• Describe energy transfer by electromagnetic and mechanical waves
• Recall and apply Ek = ½mv² in new situations
• Recall and apply Ep = mgh near the Earth's surface in new situations
• State and apply the principle of conservation of energy
• Recall and apply work done = force × distance moved in the force direction
• Recall and apply power = energy transfer / time taken
• Calculate efficiency as useful energy output / total energy input
• Evaluate prescribed electricity-generation resources by efficiency, cost, reliability and environmental impact
• Compare physical properties of solids, liquids and gases
• Explain state properties using particle arrangement, motion, forces and separation
• Infer random molecular motion from a Brownian-motion experiment
• Relate temperature rise to increased average kinetic energy of particles
• Explain gas pressure using particle collisions with container walls
• Explain heating from higher to lower temperature until thermal equilibrium
• Describe conduction in solids through particle vibration and mobile electrons
• Describe convection in fluids through density changes and bulk motion
• Explain that energy transfer by electromagnetic radiation needs no material medium
• Explain how surface colour, texture, temperature and area affect radiation transfer rate
• Apply conduction, convection and radiation in everyday systems
• describe internal energy as an energy store that is made up of the total kinetic energy associated with the random motion of the particles and the total potential energy between the particles in the system
• Define heat capacity and specific heat capacity
• Apply energy transferred = mass × specific heat capacity × temperature change
• describe melting/solidification and boiling/condensation as processes of energy transfer without a change in temperature
• Explain the difference between boiling and evaporation
• Define latent heat and specific latent heat
• Apply energy transferred for a change of state = mass × specific latent heat
• Explain latent heat using particle behaviour
• Sketch and interpret a cooling curve
• Describe wave generation by vibrating sources, ropes and springs
• Describe ripple-tank waves using wavefronts
• Explain that waves transfer energy
• Explain that wave energy transfer does not transfer matter
• Use amplitude, frequency and wavelength to describe wave motion
• Define and use wave speed and period and interpret wave graphs
• Recall and apply wave speed = frequency × wavelength
• Compare transverse and longitudinal waves and give examples
• Explain sound production by vibration and the need for a medium
• Describe sound using compressions and rarefactions
• Relate sound loudness to amplitude and pitch to frequency
• Explain reflected-sound echoes and use them to measure distance
• Explain ultrasound use in sonar and soft-tissue scanning
• State that all electromagnetic waves are transverse
• State that all electromagnetic waves travel at the same speed in vacuum
• Order the seven electromagnetic-spectrum regions
• Relate spectrum order to wavelength and frequency
• State typical uses of radio waves
• State typical uses of microwaves
• State typical uses of infrared
• State typical uses of visible light
• State typical uses of ultraviolet
• State typical uses of X-rays
• State typical uses of gamma rays
• Describe hazardous heating effects of electromagnetic over-exposure
• Describe hazardous ionising effects on living cells and tissue
• Use the normal, angle of incidence and angle of reflection
• Apply the law of reflection in constructions, measurements and calculations
• Use the normal, angle of incidence and angle of refraction
• Apply sin i divided by sin r as a constant for a fixed pair of media
• Define refractive index as vacuum light speed divided by medium light speed
• Explain the critical angle
• Explain the conditions for total internal reflection
• Apply total internal reflection to optical fibres and state advantages
• Describe how a thin converging lens acts on a light beam
• Define the focal length of a converging lens
• Construct real and virtual image ray diagrams for a thin converging lens
• Describe lens images as real or virtual, magnified or diminished, and upright or inverted
• state that there are positive and negative charges and that charge is measured in coulombs
• state that unlike charges attract and like charges repel
• Describe an electric field as a region where charge experiences force
• Recall that the field lines of an isolated point charge give the direction of the force on a positive test charge
• Draw the directed electric field of an isolated point charge
• Interpret the electric-field pattern between two isolated point charges
• Draw the electric-field pattern between two isolated point charges
• Explain charging by rubbing as electron transfer
• Describe experiments that charge a conductor by induction
• Describe potential electrostatic-charging hazards
• Describe an electrostatic precipitator and transfer the principle
• State current as rate of charge flow measured in amperes
• Distinguish conventional current from electron flow
• Apply charge equals current multiplied by time
• Define source e.m.f. as work done per unit charge around a circuit
• Calculate total e.m.f. for sources in series
• Define component potential difference as work done per unit charge
• State resistance as potential difference divided by current
• Apply resistance equals potential difference divided by current
• Apply wire-resistance proportionalities for length and cross-sectional area
• Describe the effect of temperature on metallic resistance
• Sketch and interpret required current–voltage characteristics
• Recognise and interpret circuit symbols for cells, batteries, switches, lamps, LEDs, resistors, fuses, ammeters and voltmeters
• Draw circuit diagrams with cells, batteries, switches, lamps, LEDs, fixed and variable resistors, fuses, ammeters and voltmeters
• Recognise and interpret circuit symbols for d.c. and a.c. supplies, potentiometers, bells, light-dependent resistors and thermistors
• Draw circuit diagrams with d.c. and a.c. supplies, potentiometers, bells, light-dependent resistors and thermistors
• Apply the same-current rule in series circuits
• Apply the potential-difference sum in series circuits
• Apply current conservation at parallel junctions
• Apply equal potential difference across parallel branches
• Calculate effective resistance in series
• Calculate effective resistance in parallel
• Solve whole-circuit problems using consistent quantities
• Describe variable-potential-divider action
• Describe NTC thermistor action as an input transducer
• Describe light-dependent resistor (LDR) action as an input transducer
• Solve simple NTC and LDR potential-divider problems
• Explain electrical heating in common appliances
• Apply P = VI
• Apply E = VIt
• Calculate electrical energy and cost in kWh
• Identify the hazard from damaged insulation
• Identify the hazard from overheating cables
• Identify the hazard from damp conditions
• Explain how fuses and circuit breakers protect circuits
• Choose and justify an appropriate fuse rating
• Explain why metal casings are earthed
• Explain why double-insulated appliances do not need an earth wire
• State the meanings and roles of live, neutral and earth
• Describe the wiring of a mains plug
• Explain live-wire placement of switches, fuses and circuit breakers
• State the properties of magnets
• Describe induced magnetism
• Distinguish temporary and permanent magnets
• Determine magnetic-field direction with a compass or bar magnet
• Interpret bar-magnet field patterns
• Draw the magnetic field pattern around a bar magnet and between the poles of two bar magnets
• Interpret the field pattern around a straight current-carrying wire
• Draw the magnetic field pattern around a straight current-carrying wire
• Interpret the field pattern around a current-carrying solenoid
• Draw the magnetic field pattern around a current-carrying solenoid
• Relate current magnitude and direction to magnetic field
• Describe electromagnet applications
• Describe experiments showing the force on a current-carrying conductor in a magnetic field
• Describe magnetic force on a charged-particle beam
• Predict force reversal when current or field reverses
• Use Fleming’s left-hand rule
• Explain the turning effect on a current-carrying coil
• Explain how current and turns increase the turning effect
• Describe split-ring commutator action
• Describe the effect of winding a motor coil on a soft-iron cylinder
• Deduce that a changing magnetic field can induce an e.m.f.
• Deduce that induced e.m.f. opposes the change producing it
• Deduce factors affecting induced e.m.f. magnitude
• Describe a simple a.c. generator and slip rings
• Sketch a simple a.c. generator voltage–time graph
• Describe a simple iron-cored transformer
• Apply ideal-transformer equations
• Explain cable loss and high-voltage transmission
• Describe atomic composition
• Use proton number, nucleon number and isotope
• Use and interpret nuclide notation
• Explain random and spontaneous nuclear decay
• Describe alpha, beta-minus and gamma radiation
• Compare ionising effect and penetrating power
• Use nuclide equations for radioactive decay
• Explain background radiation
• Use half-life in tables and decay curves
• State radioactivity applications and hazards
• Evaluate uses and hazards using half-life and radiation properties
• Relate fission and fusion to nuclear-energy release
• Measurements of length, mass, temperature, time interval, volume of liquids/solids and force (e.g. weight) using appropriate instruments
• Determination of the density of a liquid, or of a regularly or irregularly shaped solid that sinks in water
• Determination of the value of the acceleration of free fall
• Investigation of the effects of balanced and unbalanced forces
• The principle of moments
• Determination of the position of the centre of gravity of a plane lamina
• Investigation of the factors affecting transfer of energy by thermal processes
• Determination of heat capacities of materials
• Latent heat of substances
• The law of reflection
• Determination of the position and characteristics of an optical image formed by a plane mirror or a thin converging lens
• The refraction of light through glass blocks
• The principle of total internal reflection
• The focal length of lenses
• Determination of the speed, wavelength and frequency of waves
• Determination of the resistance of a circuit component
• Investigation of the magnetic effect of current in a conductor
• Investigation of the effects of electromagnetic induction