physics paper 1

• what happens in terms of energy when an object is projected upwards?

  it gains gravitational potential energy and kinetic energy decreases
• what happens in terms of energy when a moving object hits an obstacle 


  the kinetic energy is transferred to heat and sound and kinetic energy of the obstacle that was hit
• what happens in terms of energy when an object is accelerated by a constant force?


  work is done by a force on an object. this work is converted to the objects kinetic store.
• what happens in terms of energy when a vehicle slows down?

  the kinetic energy of the vehicle decreases while energy is dissipated through heat and sound
• what happens in terms of energy when water is brought to the boil in an electric kettle?


  energy transfers from the electrical store of the mains power supply to the thermal store of the water
• what factors affect the rate of cooling of a building?

  the thickness and thermal conductivity of its walls
• what is a conductor?

  this is the process by which energy is transferred through a material
• what is an insulator


  materials that are poor conductors
• what materials are good insulators


  non-metals and air
• how is electricity generated through wind?


  the wind has kinetic energy which turns the blades on a wind turbine, the turbine tuns and this turns a generator
• how is electricity generated through geothermal energy?


  cold water is pumped into the ground and is heated by hot rocks. the water returns to the surface as steam. the moving steam turns a turbine which turns a generator,
• what is nuclear energy?

  fission of uranium nuclei that heats water
• what is the energy source biofuel?

  gases from rotting plant material are burned to heat water
• how is electricity generated through hydroelectricity?


  water in high level reservoir stores gravitational potential energy. the water flows downhill and has kinetic energy. the water turns a turbine connected to a generator.
• how is water heated to generate electricity in a solar thermal power station?

  water is heated in a boiler which turns into steam. the steam turns a turbine which turns a generator
• what does ohms law say?

  the current through an ohmic conductor (at a constant temperature) is directly proportional to the potential difference across the resistor
• what happens to the resistance of a filament lamp as the temperature increases?

  as the temperature increases, the resistance of a filament lamp also increases
• what happens to the resistance of a thermistor as it increases in temperature?

  the resistance decreases as the temperature increases
• what happens to the resistance of a LDR as the light intensity increase?

  the resistance decreases as the light intensity increases
• name an application of a thermistor

  thermostat
• what happens to the current in series/parallel circuits?

  • series - current is the same everywhere
  • parallel - current splits
• what happens to the potential difference in series/parallel circuits?

  • series - splits across components
  • parallel - same on different paths
• what happens to the total resistance of two resistors in parallel


  the total resistance of two resistors in parallel is less than the resistance of the smallest resistor
• what do we use to measure potential difference?

  voltmeter in parallel across a componeny
• what do we use to measure current?

  an ammeter in series
• when do certain insulating materials become electrically charged?

  when they are rubbed against each other
• what happens when two electrically charged objects are brought together?

  they exert a force on each other
• what is the frequency of mains electricity?

  50 Hz
• what is the voltage of mains electricity in the UK?

  230 V
• what colour is the live wire colouring?

  brown
• what colour is the neutral wire covering?

  blue
• what colour is the earth wire covering?

  green and yellow stripes
• what does the live wire do?

  carry the alternating potetial difference from the supply
• what does the neutral wire do?

  completes the circuit
• what does the earth wire do?


  safety wire to stop the appliance from becoming live
• what is the potential difference between the earth wire and the live wire?

  230 V
• what is the potential difference of the earth wire?

  0 V
• what is the potential differences of the neutral wire?

  0 V
• when does the live wire carry the current?

  when there is a fault
• what does the amount of energy an appliance transfers depend on?

  • the power of the appliance
  • how long it is switched on for