resistance

• What equipment is used in the resistance practical?

  • Battery
  • Ammeter
  • Voltmeter
  • Length of wire
• How do you measure the current in the circuit?

  Using an ammeter
• How do you calculate resistance in the circuit?

  Resistance = Voltage / Current
• What does the experiment focus on regarding the wire?

  The length of the wire
• How can you increase the length of the wire in the circuit?

  By moving the crocodile clips apart
• What does a straight line graph through zero indicate?

  Resistance is directly proportional to length
• What is a zero error?

  A reading when the value should be zero
• Why is zero error considered a systematic error?

  It cannot be reduced by repeating measurements
• How should you adjust readings to account for zero error?

  Subtract the zero error from all readings
• What causes zero error in this experiment?

  Contact resistance and positioning of clips
• How does temperature affect resistance?

  Increased temperature raises resistance
• What can be done to reduce heating effects in the wire?

  Use a low potential difference
• When should the current be turned on during the experiment?

  Only when taking a reading
• How does a variable resistor work?

  • Contains a long piece of wire in a coil
  • Slider changes the length of wire in the circuit
  • Controls the potential difference across the load
• What happens to the lamp when resistance is increased?

  The lamp becomes dimmer
• What is the main conclusion about wire length and resistance?

  Longer wire increases resistance