Paper 1 - Required Practicals

• What is specific heat capacity?

  Energy needed to raise 1 kg by 1°C
• What factors does specific heat capacity depend on?

  Mass, energy supplied, temperature change
• How can you calculate specific heat capacity using the equation?

  Energy divided by mass times temperature change
• What does the symbol $\Delta$ represent in the specific heat capacity equation?


  Change in temperature
• What does a higher specific heat capacity indicate?

  Stores more heat energy without large temperature increase
• What happens when you heat different substances in a microwave?

  They heat up differently due to specific heat capacities
• What equipment is typically used in the specific heat capacity practical?

  • Metal block or liquid
  • Immersion heater
  • Power supply
  • Joule meter
  • Thermometer
  • Balance or weighing scales
• What is the first step in the specific heat capacity practical?

  Measure the mass of the substance
• Why is it important to record temperature every few minutes?

  To track temperature change over time
• What should you do if you don't have a joule meter in the practical?

  Use an ammeter and voltmeter to calculate energy
• How do you calculate energy if you have power and time?

  Energy equals power multiplied by time
• What does the graph of temperature over time look like in this practical?

  It has a horizontal section due to heater warm-up
• What is a common error in the specific heat capacity practical?

  Energy loss to surroundings
• How can you improve accuracy in the specific heat capacity practical?

  Use insulation around the block
• What is the independent variable in the resistance of a wire practical?

  Length of the wire
• How is resistance calculated in the wire practical?

  Resistance equals potential difference divided by current
• What equipment is needed for the resistance of a wire practical?

  • Crocodile clips
  • Wire
  • Meter ruler
  • Ammeter
  • Voltmeter
• What should you do to ensure accurate measurements in the resistance practical?

  Place crocodile clips in line with the ruler
• What happens to resistance as the length of the wire increases?

  Resistance increases due to more collisions
• Why is it important to disconnect the voltmeter between readings?

  To prevent the wire from heating up
• What is the characteristic of a fixed resistor in a graph?

  Directly proportional straight line through the origin
• What is the purpose of a variable resistor in the current-voltage characteristics practical?

  • Changes resistance
  • Allows for a range of current and PD values
• What should you do to obtain negative values for current and PD?

  Reverse the connections on the cell
• How does the graph for current-voltage characteristics differ from standard graphs?

  It includes both positive and negative values
• What does a filament bulb's graph look like?

  Non-linear, indicating resistance changes with current
• What is the equation for calculating resistance?

  Resistance equals potential difference divided by current
• What is the role of an ammeter in a circuit?

  Measures the current flowing through the circuit
• What does a voltmeter measure?

  Potential difference or voltage
• What is the symbol for a fixed resistor in a circuit diagram?

  Rectangle
• What is the symbol for a variable resistor in a circuit diagram?

  Arrow through a rectangle
• What is the characteristic of a diode in a circuit?

  Allows current to flow in one direction
• What is the purpose of a light-emitting diode (LED)?

  Emits light when current flows through it
• How does the current-voltage characteristic of a diode differ from that of a resistor?

  Diodes have a non-linear relationship
• What is the significance of plotting current against potential difference?

  Shows how they vary for different components
• What is the typical shape of a current-voltage graph for a filament bulb?

  Curved, indicating increasing resistance
• What does a straight line through the origin indicate in a current-voltage graph?

  Directly proportional relationship between current and voltage
• Why is it important to have a range of values in experiments?

  To identify trends and relationships accurately
• What is the role of a power source in a circuit?

  Provides energy to drive current through the circuit
• What is the unit of resistance?

  Ohm
• What does a voltmeter measure in a circuit?

  Potential difference across components