YR 8 - Physics [Electricity + Magnetism] Flashcards
(20 cards)
What is current?
Current is a flow of charge (electrons).
What needs to be present for a current to flow?
For a current to flow there must be a source of potential difference.
What provides the potential difference?
The cell provides the potential difference.
What is a series circuit?
Components next to each other in a circuit loop are said to be in series.
What is a parallel circuit?
Components on different branches in a circuit are said to be parallel.
What is current measured in and what can be used to measure it?
Current is measured in Amps (A) using an ammeter connected in series.
What is potential difference measured in and what can be used to measure it?
Potential difference is measured in Volts (V) using a voltmeter connected in parallel.
How is potential difference shared in a series circuit?
Potential difference is shared across components in series circuits.
How is potential difference shared in a parallel circuit?
Potential difference is the same across components in parallel.
What does adding cells do?
Adding cells increases current in a circuit.
What does adding bulbs in a series circuit do?
Adding bulbs in a series reduces current flow and increases resistance.
What does adding branches in a parallel circuit do?
Adding branches in parallel increases current by decreasing resistance.
What is present when a current flows through a wire?
When a current flow through a wire a magnetic field is present around the wire.
What is resistance and what is it measured in?
Resistance is the opposition to the current measured in Ohms.
What is the equation for voltage?
Voltage (V) = I (Current) x R (Resistance)
Why are electromagnets useful?
Electromagnets can be switched on and off making them useful.
When are electromagnets only magnets?
Electromagnets are only magnets while the current flows.
How can you increase the strength of an electromagnet?
The strength of an electromagnet can be increased by adding more coils of wire or by increasing the current.
How can the direction of a magnetic field around an electromagnet be reversed?
The direction of the magnetic field around an electromagnet can be reversed by reversing the current direction.
When do magnetic materials experience a force?
Magnetic materials experience a force when in a magnetic field.
