Physics Study Notes
Junior Cert Science

Here is a summary of the main concepts that you need to know for each of the Junior Cert Physics chapters (as laid out in EDCO's Exploring Science. There are also examples of mindmaps created by students in St Colmcille's CS. Feel free to look at these mindmaps but remember that the learning happens when you make your own.

Underlined concepts are higher level only.

31 - Measurement

  • OP1    Measure length, mass, time and temperature (SI units); perform simple calculations based on these to find the derived quantities: area and volume.
  •     Understand that units of measurement follow the SI system.

​32 – Density & Flotation

  • OP2   Measure mass and volume of a variety of solids and liquids and hence determine their densities.
  • OP3   Investigate flotation for a variety of solids and liquids in water and other liquids, and relate the results of this investigation to their densities.

33 - Motion

  • OP1    Perform simple calculations to find the derived quantities: speed, velocity, and acceleration

34 - Force

  • OP4     Appreciate the concept of force, recall that the newton is the unit of force, and describe forces and their effects
  • OP5     Investigate examples of friction and the effect of lubrication
  •  OP6     Investigate the relationship between the extension of a spring and the applied force
  • OP7    Recall that weight is the force of gravity and that weight can vary with location; recall that mass in kilograms multiplied by 10 is approximately equal in magnitude to weight in newtons on the surface of the earth.

​35 – Moments, Levers & Centre of Gravity

  • OP8   Find the centre of gravity of a thin lamina. Investigate the role of centre of gravity in design for stability and equilibrium
  • OP9   Investigate the law of the lever; recall two everyday applications of levers

36 -Pressure

  • OP10     State the relationship between pressure, force and area; perform simple calculations using this relationship
  • OP11     Investigate the relationship between pressure and depth for a liquid
  • OP12    Show that air has mass and occupies space
  • OP13     Associate change in the pressure exerted by the atmosphere with change in altitude
  • OP14     Examine weather charts to observe variations in atmospheric pressure and relate these to weather conditions

37 – Work, Energy & Power


  • OP15     Define and give the units for work, energy and power, state the relationship between work and power, and perform simple calculations based on this relationship
  • OP16     Classify sources of energy as renewable or non-renewable
  • OP17    State the principle of conservation of energy
  • OP18    Explain why the sun is considered our primary source of energy and how this is important in food production and energy supply
  • OP19    List the advantages and disadvantages of different energy sources, including nuclear sources of energy, as part of the solution to national energy needs
  • OP20    Identify different forms of energy and carry out simple experiments to show the following energy conversions:
  • Chemical energy to electrical energy to heat energy
  • Electrical energy to magnetic energy to kinetic energy
  • Light energy to electrical energy to kinetic energy
  • OP21    Give examples of energy conversions from everyday experience.

38 - Heat

  • OP22     Recall that heat is a form of energy and that it can be converted into other forms of energy
  • OP23     Investigate and describe the expansion of solids, liquids and gases when heated, and contraction when cooled
  • OP24     Demonstrate the expansion of water on freezing
  • OP25     Measure the temperature of various solids and liquids at, above and below room temperature; determine the melting point of ice and the boiling point of water
  • OP26     Investigate the effect of pressure on the boiling point of water
  • OP27     Explain the difference between heat and temperature
  • OP28     Carry out experiments that involve changes of state from
  •     i. solid to liquid and liquid to solid
  •     ii. liquid to gas and gas to liquid
  • OP29     Plot a cooling curve and explain the shape of the curve in terms of latent heat
  • OP30     Appreciate that all hot bodies radiate heat
  • OP31     Carry out simple experiments to show the transfer of heat energy by conduction, convection and radiation; investigate conduction and convection in water
  • OP32     Identify good and bad conductors of heat and compare insulating ability of different materials.

39 - Light

  • OP33   Recall that light is a form of energy and that it can be converted into other forms of energy
  • OP34  Show that light travels in straight lines and explain how shadows are formed.
  • OP35  Contrast luminous objects, which are themselves a source of light, with non-luminous objects, which are seen because light is reflected from them.
  • OP36  Recall that white light is made up of different colours which can be separated by dispersion.
  • OP37  Produce a spectrum of white light using appropriate apparatus, and list the colours of the spectrum.
  • OP38  Investigate the reflection of light by plane mirrors, and illustrate this using ray diagrams.  Demonstrate and explain the operation of a simple periscope.
  • OP39  Show the refraction of light as it passes from: air to glass, air to water, glass to air, water to air,  Show refraction of light through a lens.   Demonstrate the operation of a magnifying glass.

40 - Sound

  • OP40    Show that sound is a form of energy, and explain that sound is produced by vibrations
  • OP41    Show that sound transmission requires a medium and that echoes are reflected sound
  • OP42    Appreciate that the ear detects sound vibrations and that exposure to very loud sounds can cause damage to hearing
  • OP43     Recall that the speed of sound is less than the speed of light
  • OP44     Explain the time lag between seeing and hearing the same event

41 - Magnetism

  • OP45   Carry out simple experiments to show attraction and repulsion between magnets, and test a variety of   materials for magnetism
  • OP46  Plot the magnetic field of a bar magnet
  • OP47   Demonstrate that the Earth has a magnetic field, and locate North and South.

​42 – Static & Current Electricity

  • OP48  Use simple materials to generate static electricity; demonstrate the force between charged objects and the effects of earthing.
  • OP49   Test electrical conduction in a variety of materials, and classify each material as a conductor or insulator
  • OP50   Set up a simple electric circuit, use appropriate instruments to measure current, potential difference (voltage) and resistance, and establish the relationship between them
  • OP51   Demonstrate simple series and parallel circuits containing a switch and two bulbs
  • OP52   Perform simple calculations based on the relationship between current, potential difference (voltage), and resistance 

​43 – Uses of Electricity

  • OP53   Describe the heating effect, the chemical effect, and the magnetic effect of an electric current, and identify everyday applications of these, including the action of a fuse
  • OP54   Distinguish between direct and alternating current; recall that the voltage of the mains supply is 230 volts a.c.
  • OP55   Recall that the unit of electrical energy used by electricity supply companies is the kilowatt-hour, and calculate the cost of using common electrical appliances, based on their power rating
  • OP56   Describe how to wire a plug correctly, and explain the safety role of a fuse or circuit breaker in domestic electrical circuits.

44 - Electronics

  • OP57     Describe a diode as a device that allows current to flow in one direction only and recall that a light emitting diode (LED) requires less current than a bulb  
  • OP58     Set up simple series circuits using switches, buzzers, LEDs and resistors 
  • OP59     Measure the resistance of a light-dependent resistor (LDR) under varying degrees of brightness of light ​ 
  • OP60     Identify everyday applications of the diode, including the LED, and of the LDR