⚡ Electricity Flashcards
(10 cards)
What is the difference between current and potential difference?
Current is the flow of charge (A); potential difference is the energy per unit charge (V).
What is resistance, and how is it calculated?
Resistance is how much a component slows current. Resistance = potential difference ÷ current (Ω = V ÷ A)
What happens to the resistance of a filament bulb as current increases?
Resistance increases because the filament gets hotter, increasing collisions in the wire.
How does a thermistor’s resistance change with temperature?
As temperature increases, resistance decreases.
How does a series circuit behave in terms of voltage and current?
Current is the same everywhere; voltage is shared between components.
How does a parallel circuit behave in terms of voltage and current?
Voltage is the same across each branch; current splits across branches.
What are the functions of the live, neutral, and earth wires?
Live carries current to the appliance, neutral completes the circuit, earth provides a safety path if a fault occurs.
What safety device breaks the circuit if current is too high?
Fuse or circuit breaker.
What is power in electrical circuits, and how is it calculated?
Power is the rate at which electrical energy is transferred or used.
Power = potential difference × current (W = V × A)
Why is energy lost as heat in power cables, and how can it be reduced?
Resistance in wires causes heat loss; reduced by using thicker wires or high voltage transmission.
