CP9 Electricity

• What is the flow of electrons in a circuit called?

  Electron flow
• What type of circuit has components connected end-to-end?

  Series circuit
• What type of circuit has components connected across common points?

  Parallel circuit
• What is the unit of electric current?

  Ampere, A
• What instrument measures electric current?

  Ammeter
• What is the unit of potential difference?

  Volt, V
• What instrument measures potential difference?

  Voltmeter
• How does current behave in series circuits?

  It is the same throughout the circuit
• How does current behave in parallel circuits?

  It divides among the branches
• How does potential difference behave in series circuits?

  It divides among the components
• How does potential difference behave in parallel circuits?

  It is the same across all branches
• What is the definition of charge?

  Electric property of matter
• What is the unit of charge?

  Coulomb, C
• How do you calculate charge?

  Charge = current × time
• What does the term "volts" refer to?

  Unit of potential difference
• How do you calculate energy?

  Energy = charge × potential difference
• What is the definition of resistance?

  Opposition to current flow
• What is the unit of resistance?

  Ohm, Ω
• What does high resistance indicate?

  Low current flow
• What does low resistance indicate?

  High current flow
• How do you calculate current?

  Current = voltage / resistance
• What are resistors?

  Components that resist current flow
• How do resistors behave in series circuits?

  Voltage adds up across resistors
• How do resistors behave in parallel circuits?

  Voltage is the same across all resistors
• What is a variable resistor?

  Resistor with adjustable resistance
• How does resistance change with light intensity for a light dependent resistor?

  Resistance decreases with increased light intensity
• What is an LDR?

  Light dependent resistor
• What is a thermistor?

  Temperature dependent resistor
• What is a diode?

  Component allowing current in one direction
• What does a filament graph show?

  Relationship between current and temperature
• What is the aim of the core practical investigating resistance?

  To investigate resistance in circuits
• What is involved in investigating series circuits?

  Measuring current and voltage across components
• What is involved in investigating parallel circuits?

  Measuring current and voltage across branches
• What do results in resistance investigations show?

  Relationship between voltage and current
• How do you calculate energy transfer?

  Energy transfer = power × time
• What is electrical energy?

  Energy from electric charges
• How can you reduce resistance?

  By using thicker wires or shorter lengths
• What is the unit of power?

  Watts, W
• How is power related to work done?

  Power = work done / time
• How is power related to voltage and current?

  Power = voltage × current