Science energy

• What is the equation for current?

  Current = charge ÷ time
• What is the equation for charge?

  Charge = current × time
• What is the equation for potential difference?

  Potential difference = current × resistance
• What is the equation for power?

  Power = potential difference × current
• What is another equation for power?

  Power = current² × resistance
• What is the equation for energy transferred?

  Energy transferred = charge × potential difference
• What is another equation for energy transferred?

  Energy transferred = power × time
• What is the equation for potential difference in terms of energy?

  Potential difference = Energy ÷ charge
• What are the components of the three core cable?

  • Live: Brown/Red, carries electricity, 230V
  • Neutral: Blue, carries current back to supply
  • Earth: Green and yellow striped, provides safe route for current
• What is the function of the live wire in a three core cable?

  • Carries electricity
  • Voltage is 230V
  • Provides low resistance path for current to flow back
• What is the function of the neutral wire in a three core cable?

  • Carries current back to the supply
• What is the function of the earth wire in a three core cable?

  • Protects appliance and user
  • Provides safe route for current to flow back
  • Reduces current if a fault occurs
• What does Ohm's Law state?

  • Current is directly proportional to potential difference
  • Temperature must remain constant
• How does a filament lamp behave in relation to current and potential difference?

  • Current does not increase proportionally with potential difference
  • Resistance increases as temperature increases
• What is the behavior of a diode in a circuit?

  • Current only flows in one direction
  • Resistance is very high when reverse biased
• How does the resistance of a filament lamp change with temperature?

  The resistance increases as the temperature increases
• What happens to current in a diode when it is reverse biased?

  Resistance is very high
• What is the relationship between current and potential difference across a resistor at constant temperature?

  The current through a resistor is directly proportional to the potential difference across it.
• What is a fuse and how does it work in a plug?

  A fuse is a safety device that melts to break the circuit if the current exceeds a certain level.
• How can you calculate the current flow in an appliance?

  Current (I) can be calculated using the formula: $I =$$\frac{P}{V}$, where P is power and V is voltage.
• What is the equation for electrical power?

  The equation for electrical power is $P =$$V \times I$ and $P =$$I^2R$.
• What is the purpose of a series of cables and transformers linking power stations to consumers?

  They are used to transmit electrical energy from power stations to consumers.
• How do you measure the frequency of AC current?

  Frequency of AC current can be measured using an oscilloscope.
• How can you differentiate between DC and AC current using an oscilloscope?

  • DC current shows a constant voltage level.
  • AC current shows a waveform that oscillates over time.
• What is the role of electrical insulators in materials?

  Electrical insulators prevent the flow of electric current.
• Why is it important to know the costing of materials used in electrical installations?

  It is important for budgeting and ensuring cost-effectiveness in electrical projects.
• How can you find the current through a resistor if you know the power and voltage?

  You can find the current using the formula: $I =$$\frac{P}{V}$.
• What can we conclude about the current flow in several appliances connected in series?

  The current is the same through all appliances connected in series.
• Who are the presenters of the Bitesize Physics Podcast?

  James Stewart and Ellie Hurer
• What are the two key concepts discussed in Episode 1 of the podcast?

  • Electrical charge
  • Current
• What are the two types of electric charge?

  Positive and negative
• What is electrical current?

  The flow of electrically charged particles through a conductor
• How is current measured?

  In amps using an ammeter
• What is the relationship of current in a single closed loop circuit?

  The current is the same at any point in the circuit
• What are the two types of electric current?

  Alternating current (AC) and direct current (DC)
• How does direct current (DC) flow in a circuit?

  Electrons flow in one direction
• How does alternating current (AC) flow in a circuit?

  The direction of electron flow continually reverses
• What is potential difference also known as?

  Voltage
• How do you measure potential difference in a circuit?

  By placing a voltmeter in parallel with a component
• What is the equation for calculating charge flow?

  Charge equals current multiplied by time