magnetism and electromagnetism (p2) Flashcards
How will like poles (north & north or south & south) behave when they interact?
They will repel and push away from each other
How will opposite poles (north & south or south & north) behave when they interact?
They will attract and pull towards each other
Is the magnetic force a contact or a non-contact force?
Non-contact
On a magnet, where is the magnetic field strongest?
The magnetic field is strongest at the poles of a magnetic
What is a permanent magnet?
A magnet that produces its own magnetic field
What is an induced magnet?
A material that becomes magnetic when it is placed in a magnetic field
What is the difference between a permanent and an induced magnet?
A permanent magnet always has a magnetic field, but an induced magnet only becomes magnetic when it is placed into a magnetic field
What is a magnetic field?
The region of space where a magnetic force will act on a magnet or a magnetic material
What are the four types of magnetic material?
Iron, nickel, cobalt and steel
Is the force between a magnet and a magnetic material attractive or repulsive?
Attractive
What shape is the magnetic field around a bar magnet?
Many loops going from the North pole to the South pole
In which direction should magnetic field lines point?
Magnetic field lines point towards the south pole of the magnet
What is a magnetic compass?
A small bar magnet mounted on a pin so that it can spin around. It will point in the direction of a nearby magnetic field
What does the strength of a magnetic field depend on?
The strength of the magnet AND the distance from the magnet
Is the magnetic field around the Earth permanent or induced?
permanent
What is a solenoid?
A coil of current-carrying wire
What is an electromagnet?
A solenoid (coil of current-carrying wire) with an iron core
What is the shape of the magnetic field around a wire?
Circular field lines around the wire
What is the shape of the magnetic field around an electromagnet?
Similar shape to the field around a bar magnet: many loops going from one end to the other end
How can a magnetic field be produced around a metal wire?
When current flows through the wire
What does the strength of a magnetic field around a wire depend on?
The size of the current in the wire AND the distance from the magnet
[ππΆπ΄π΅π²πΏ π§πΆπ²πΏ] What is the motor effect?
When a conductor carrying a current is placed in a magnetic field the magnet producing the field and the conductor exert a force on each other
[ππΆπ΄π΅π²πΏ π§πΆπ²πΏ] In Flemingβs left hand rule, state what the thumb represents
Force (measured in Newtons, N)
[ππΆπ΄π΅π²πΏ π§πΆπ²πΏ] In Flemingβs left hand rule, state what the first finger represents
Magnetic flux density (measured in Tesla, T)
[ππΆπ΄π΅π²πΏ π§πΆπ²πΏ] In Flemingβs left hand rule, state what the middle finger represents
Current (measured in Amps, A)
[ππΆπ΄π΅π²πΏ π§πΆπ²πΏ] What affects the size of the force on the wire in the motor effect?
The size of the magnetic field, the size of the current in the conductor, the length of the conductor that is in the magnetic field
[ππΆπ΄π΅π²πΏ π§πΆπ²πΏ] Describe how an electric motor works
A coil of wire carrying a current in a magnetic field will experience a force on opposite sides of the wire - this is because the direction of the force depends on the direction of the current. These opposite forces cause the wire to rotate
