Electricity

• What is the topic summary for AQA Physics electricity?

  Electricity and its practical applications
• What are the core practicals for electricity?

  • Key experiments in electricity
  • Available in free version guide
  • Purchase on Amazon
• What is a cell in an electrical circuit?

  A single source of electrical energy
• What is a battery in an electrical circuit?

  More than one cell combined
• What does an ammeter measure?

  Current in amps
• What does a voltmeter measure?

  Potential difference in volts
• What is a lamp or bulb used for in a circuit?

  To provide light
• What is a diode?

  A component allowing current in one direction
• What is an LED?

  A light-emitting diode
• What is a resistor used for in a circuit?

  To limit current flow
• What is a variable resistor?

  A resistor with adjustable resistance
• What is a fuse?

  A safety device that melts with excess current
• What is a thermistor?

  A resistor that changes with temperature
• What is a light-dependent resistor (LDR)?

  A resistor that changes with light levels
• How does a series circuit function?

  Current flows through all components sequentially
• How does a parallel circuit function?

  Current splits into multiple branches
• What is charge in an electrical circuit?

  Value of electricity flowing through circuits
• How is current measured?

  In amps
• How is time measured in electrical circuits?

  In seconds
• What does potential difference do in a circuit?

  It pushes the current around
• What is the formula for charge?

  Charge = current times time
• How is potential difference calculated?

  Potential difference = current times resistance
• What is the relationship between current and potential difference in a resistor at constant temperature?

  They are directly proportional
• What does the graph of a filament bulb show?

  Resistance increases as temperature increases
• How does a diode behave in a circuit?

  It allows current to flow in one direction
• How does temperature affect a thermistor's resistance?

  Resistance changes with temperature
• How does a light-dependent resistor (LDR) function?

  Resistance changes with light levels
• How does current behave in a series circuit?

  It remains the same throughout
• How does current behave in a parallel circuit?

  It splits among branches
• How is total resistance calculated in series circuits?

  By adding all resistances together
• How is total resistance calculated in parallel circuits?

  Using the formula: 1/R_total = 1/R1 + 1/R2 + ...
• What is the mains electricity voltage in the UK?

  230 volts
• What is the frequency of mains electricity in the UK?

  50 Hertz
• What is the function of a fuse in a plug?

  To melt and break the circuit if current is too high
• What are the three wires in a plug?

  Live, neutral, and earth wires
• What is the purpose of the earth wire in a plug?

  To prevent electric shock by grounding
• What is the purpose of the neutral wire in a plug?

  To complete the circuit back to the power source
• What is the purpose of the live wire in a plug?

  To carry current to the appliance
• What is the formula for power?

  Power = potential difference times current
• How is power measured?

  In watts