Electrical current

• Entry Level Certificate
• Electrical current


  The flow (movement) of electrical charge
• Size of the current

  How much charge is flowing per second
• A circuit diagram shows how to build a circuit
• Components


  The parts of the circuit connected by the leads
• Current is measured in amps using an ammeter
• Voltage is measured in volts using a voltmeter
• Investigating current


  1. Switch on the circuit and measure the current and voltage

  2. Change the voltage and measure the current and voltage

  3. Repeat until you have at least three readings
• Increasing the voltage across the component increases the current through it
• Resistance


  How difficult it is for a current to pass through a component
• Increasing the resistance in a circuit decreases the current through it
• Components


  • Bulb
  • Motor
  • Buzzer
• Good conductors will have a lower resistance to the electrical current than a poor conductor
• Current is measured using an ammeter
• Current is measured in amps
• Electrical current is the flow of electrical charge
• The size of the current is the rate of flow of charge
• Different components have different resistances
• Table 2 shows the currents when different components are connected to a battery
• The component with the lowest current is the buzzer
• The motor will have the lowest resistance because it has the highest current
• Increasing the voltage across a component affects the current flowing through it