Paper 1 Physics

• Renewable energy resource


  An energy source which can be replenished as it is being used up
• Non-renewable energy resource


  Fossil fuels (for example coal, oil and gas)
• Advantages of generating power using gas rather than coal

  • Flexible Generation: Gas power stations have short start-up times so can be switched on/off more readily
  • Lower emissions of carbon dioxide
• Disadvantages of using renewable energy resources to generate power

  • Output often determined by external factors (like wind speed), so supply is uncertain
  • Generating power through other means is often more efficient and economically beneficial
• Burning fossil fuels


  • Carbon Dioxide contributes to the greenhouse effect, and causes global warming
  • Sulphur Dioxide leads to acid rain, which can damage buildings and crops
• Advantages of fossil fuels as an energy resource

  • Reliable: Not dependent on external factors so can generate power anytime
  • Can produce large amounts of energy for a given quantity
  • Still relatively abundant, so cost-effective
• Advantages of nuclear power

  • Very large amounts of energy for relatively small quantities of fuel
  • Doesn't release greenhouse gases and so doesn't contribute to climate change
  • Low fuel costs
• Disadvantages of nuclear power

  • Produces nuclear waste which is harmful to humans & must be safely stored for centuries
  • Non-Renewable energy source
  • Risk of nuclear accidents, which have fatal consequences on humans and the environment
• How hydroelectric power produces energy

  1. Rainwater collects behind a dam

  2. When this water is released, it is used to turn a turbine

  3. This turbine turns a generator which produces electricity
• Disadvantages of using biofuels

  • When plants are burned or decay they release CO2
  • In order to grow biofuels, you need to destroy land which leads to problems because: The land could have been natural habitats, Destroying land may involve burning plants growing on it, which would release CO2
  • Growing biofuels reduces the land available for growing food
• Advantages of tidal energy sources

  • They do not produce greenhouse gases
  • They are quite reliable, as tides happen twice a day
  • They are cheap to run as tides are natural, and so are free
• Disadvantages of hydroelectric power

  • The dam may cause flooding
  • It can cost a lot to install the required infrastructure
• Advantages of solar panels

  • They don't cause harm to the environment
  • They are a renewable resource
  • They can be used in remote areas where other types of energy are less accessible
• Social factors which may act as a deterrent for certain types of energy production

  • Visual Pollution
  • Sound Pollution
• Cell


  Circuit symbol
• Battery


  Circuit symbol
• Lamp


  Circuit symbol
• Fuse


  Circuit symbol
• Voltmeter


  Circuit symbol
• Ammeter


  Circuit symbol
• Diode


  Circuit symbol
• Resistor


  Circuit symbol
• Thermistor


  Circuit symbol
• Variable resistor


  Circuit symbol
• LDR (Light Dependent Resistor)


  Circuit symbol
• LED (Light Emitting Diode)


  Circuit symbol
• Electric current


  The flow of electrical charge
• Equation linking charge, current and time

  1. Q = I t

  2. Charge (Coulombs)

  3. Current (Amperes)

  4. Time (Seconds)
• Current is the same at all points in a closed loop
• Factors current in a circuit depends on

  • 1. Potential Difference (V)
  • 2. Resistance (R)
• Equation to calculate potential difference if current and resistance are known

  1. V = I R

  2. Potential Difference (V)

  3. Current (A)

  4. Resistance (Ω)
• Ohmic Conductor


  • A conductor for which current and potential difference are directly proportional
  • Resistance remains constant as current changes
  • Temperature must be constant
• Components for which resistance is not constant as current changes

  • Lamps
  • Diodes
  • Thermistors
  • Light Dependant Resistors (LDRs)
• Resistance of a filament lamp as temperature increases

  • Resistance increases
  • Ions in metal have more energy, so vibrate more, causing more collisions with electrons as they flow through the metal, creating greater resistance to current flow
• Current flow through a diode

  • The current only flows in one direction
  • Resistance is very high in the other direction, preventing current flow
• Resistance of a thermistor as temperature increases

  The thermistor's resistance decreases
• When a thermistor may be used

  • In a thermostat to turn a heater on below a certain temperature
  • In a freezer to turn on a cooler when the temperature becomes too high
• Resistance of a LDR as light intensity decreases


  The LDR's resistance increases
• Application for a LDR


  • Street lights often use LDRs
  • When light levels become too low, the light gains sufficient current to turn on
• Series


  Same loop