Current & Mains Electricity Flashcards
(24 cards)
What is electric current?
The flow of electric charge (electrons) around a circuit.
What is the unit of current?
Amp (A)
What is the equation linking current, charge, and time?
Charge = Current × Time (Q = I × t)
What causes current to flow?
A potential difference (voltage) across the circuit
What is the current like in a series circuit?
The same at every point.
What is the current like in a parallel circuit?
It splits across branches and recombines.
What happens to total current in a parallel circuit?
It equals the sum of currents in each branch.
What is resistance?
A measure of how much a component resists the flow of current.
What is the formula for Ohm’s Law?
Voltage = Current × Resistance (V = I × R)
What is the unit of resistance?
Ohm (Ω)
What is the frequency of UK mains electricity?
50 Hz
What is the voltage of UK mains electricity?
230 V
What type of current is mains electricity?
Alternating Current (AC)
What type of current is supplied by batteries?
Direct Current (DC)
What does AC mean?
The current changes direction regularly.
What does DC mean?
The current flows in one direction only.
What colour is the live wire in a UK plug?
Brown
What colour is the neutral wire?
Blue
What colour is the earth wire?
Green and yellow stripes
What is the purpose of the live wire?
It carries the current to the appliance at high voltage.
What is the purpose of the neutral wire?
It completes the circuit and carries current away.
What is the purpose of the earth wire?
It provides a path to ground if the appliance casing becomes live.
What safety feature melts if too much current flows?
The fuse
What is the role of a fuse in a plug?
It melts and breaks the circuit if the current is too high, preventing damage or fire.
