GCSE physics - Electricity

    Cards (30)

    • What is required for electrical charge to flow in a circuit?
      A closed circuit and a source of potential difference
    • What is electrical current?
      Current is the flow of electrical charge
    • How is charge flow (Q) calculated in terms of current (I) and time (t)?
      Q = It
    • What does the current (I) through a component depend on?
      The resistance (R) of the component and the potential difference (V) across it
    • How does resistance affect current for a given potential difference?
      Greater resistance results in smaller current
    • What is the equation that relates potential difference (V), current (I), and resistance (R)?
      V = IR
    • What characterizes an ohmic conductor in terms of resistance and potential difference?
      Current is directly proportional to potential difference, resulting in a linear graph
    • How does the resistance of a filament lamp change with temperature?
      The resistance increases as the temperature of the filament increases
    • What is the behavior of current through a diode?
      Current flows in one direction only, with higher resistance in the reverse direction
    • How does resistance change with current in a thermistor?
      Resistance decreases as current increases
    • How does the length of a wire affect its resistance?
      Greater length results in more resistance and lower current
    • What happens to the resistance of an LDR (Light Dependent Resistor) with light intensity?
      Resistance decreases as light intensity increases
    • What is the function of a diode in a circuit?
      A diode allows current to flow freely in one direction
    • What are the characteristics of series circuits?
      • Current is the same everywhere
      • Total resistance is the sum of individual resistances
      • Potential difference is shared across components
      • Components are connected end to end
    • What are the characteristics of parallel circuits?
      • Current splits into multiple paths
      • Total current into a junction equals total current in branches
      • Potential difference is the same across each branch
      • Total resistance is less than the smallest resistor
    • What is the frequency and voltage of mains electricity in the UK?
      50 Hz and about 230 V
    • What is the role of the live wire in a plug?
      The live wire carries the alternating potential difference from the supply
    • What is the purpose of the earth wire in a plug?
      The earth wire is a safety wire that carries current only if there is a fault
    • How is power defined in electrical terms?
      Power is the energy transferred per second
    • How is energy transferred calculated using power and time?
      E = Pt
    • How is energy transferred calculated using charge and potential difference?
      E = QV
    • What are the energy transfers in everyday appliances?

      • Kinetic energy for motors
      • Thermal energy in kettles
      • Work done when charge flows through a circuit
    • What is the National Grid?
      The National Grid is a system of cables and transformers linking power stations to consumers
    • What do step-up transformers do?
      They increase the potential difference from the power station to the National Grid
    • What do step-down transformers do?
      They decrease the potential difference from the National Grid to consumers
    • What is static electricity?
      Static electricity is the buildup of electric charge on the surface of objects
    • What happens when two insulators are rubbed together?
      Electrons are transferred from one object to the other, creating a positive and negative charge
    • What is the electrostatic force?
      It is the force of attraction or repulsion between charged objects
    • How does the distance between charged objects affect the electrostatic force?

      The force is proportional to the inverse square of the distance between the objects
    • What are the characteristics of electric fields?
      • They point in the direction a positive charge would go
      • They point away from positive charges and towards negative charges
      • Stronger charges have more field lines and a stronger force
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