Section B Electricity Flashcards
(20 cards)
In which type of circuit is current conserved?
Parallel circuits.
What type of current flows from batteries?
DC currents. They flow from solar cells and batteries.
What type of current flows from electricity mains?
AC currents.
What does AC stand for?
Alternating current.
What does DC stand for?
Direct current.
What is power measured in?
Watts.
What is current measured in?
Amperes (amps)
What is insulation?
When the conducting part of the wire is covered (protected) with plastics (PVC) and so they become safe.
What is the current in a circuit?
The rate of flow of charge round the circuit.
What is voltage?
The driving force that pushes the current round the circuit.
What is the resistance?
Anything in the circuit which slows the flow down.
What is the unit for resistance?
Ohms (omegle sign)
What is the equation linking electrical power, current and voltage?
Electrical power = current x voltage
What is double insulation?
Prevents electrocution by using an outer casing made up of plastics with appliances such as refrigerators, toasters and kitchen appliances.
What does an ammeter do in a test circuit?
Measures the current. ONLY in series. Never in parallel.
What is a voltmeter?
Measures the voltage (in volts). Are always connected in parallel with a component, even in a series circuit.
How do you calculate the energy transferred by an appliance?
Energy transferred = current x voltage x time
What is the equation for measuring voltage?
Voltage = Current x Resistance
Where must an ammeter be placed in a circuit?
Anywhere in the main circuit, but never in parallel.
What are circuit breakers?
They break the circuit when they detect a surge in the current. They break the circuit by opening a switch.
