P2: Magnetism & Electromagnetism Flashcards
The microphone is used to convert the pressure variations in sound waves into variations in ______
Current.
What material is used in the core of a transformer?
Iron, because it is easily magnetised
Why do we use iron as the core in a transformer?
Because it is easily magnetised.
What is a solenoid?
A long insulated coil of wire.
List some of the magnetic metals.
Iron, cobalt, nickel.
What is induced magnetism?
When an object becomes magnetic when it is placed in a magnetic field.
How is induced magnetism lost?
When the magnet moves out of the magnetic field.
Where is the magnetic force of a magnet at its strongest?
Near its poles.
What is the direction of magnetic field lines?
North to South
What type of force is magnetism?
Non-contact.
How can you show that an object is a permanent magnet?
By checking if it repels another magnet.
What equipment do you need to draw out magnetic field lines?
A bar magnet, a plotting compass, paper and a pencil.
The closer the field lines, the __ the magnetic field.
Stronger.
What is Fleming’s left hand rule?
-Thumb shows direction of Force
-First finger shows direction of Magnetic Field
-Second finger shows direction of Electrical Current
What strengthens the magnetic field of a wire?
-Increasing current of the wire.