Magnetism And Electromagnetism Flashcards
(25 cards)
At which part of a magnet are the magnetic forces strongest?
At the poles
What happens when two magnets are brought close to each other?
They exert force on each other
What happens when two like poles are brought together?
Repel
What happens when two unlike poles are brought together?
Attraction
What is the difference between a permanent magnet and an induced magnet?
Permanent magnet produces its own magnetic field
Induced magnet becomes magnetic when placed in a magnetic field
What type of force does induced magnetism always cause?
Force of attraction
What happens when an induced magnet is removed from a magnetic field?
Loses most/all of its magnetism
What is a magnetic field?
The region surrounding a magnet where another magnet or magnetic material experiences a non-contact force
Give four examples of magnetic materials:
Iron
Steel
Cobalt
Nickel
What direction does a magnetic field point?
From the north to the south
What does a magnetic compass contain?
A small bar magnet that points in the direction of the Earth’s magnetic field
What is produced when current flows through a conducting wire?
A magnetic field is produced around the wire
What determines the strength of the magnetic field around a current carrying wire?
The magnitude of the current flowing through the wire
The distance from the wire
What is a solenoid?
A coil wire which when current passes through creates a strong magnetic field
Describe the magnetic field inside a solenoid:
Strong and uniform
What is an electromagnet?
A solenoid with an added iron core
Adding the iron core increases the strength of the magnetic field
What is the motor effect?
When a force is exerted between a magnetic field and a current carrying conductor placed in that field
What rule is used to determine the force experienced due to the motor effect?
Fleming’s left hand rule
What does the first finger represent in Fleming’s left hand rule?
Magnetic field
What does the second finger represent in Fleming’s left hand rule?
Direction of current
What factors affect the size of the force on a current carrying wire in a magnetic field?
The magnitude of the current flowing through the conductor
The strength of the magnetic field that the conductor is placed in
If the direction of current in a current carrying wire placed in a uniform magnetic field is reversed what happens to the force?
The direction of the force is reversed
What is the unit used for magnetic flux density?
Tesla, T
How does an electric motor work?
A coil of wire, carrying a current, is placed in a magnetic field
The forces on the two sides perpendicular to the field experience forces in opposite directions
Causes a rotational effect
