Magnetism and electromagnetism Flashcards
Where are the poles of a magnet?
The poles of a magnet are the places where the magnetic forces are strongest. When two magnets are brought close together they exert a force on each other. Two like poles repel each other. Two
unlike poles attract each other. Attraction and repulsion between two magnetic poles are examples of non-contact force.
What does a permanent magnet produce?
A permanent magnet produces its own magnetic field
What is an induced magnet?
An induced magnet is a material that becomes a magnet when it is placed in a
magnetic field. Induced magnetism always causes a force of attraction.
What happens when a induced magnet is removed from its magnetic field?
When removed from the magnetic field an induced
magnet loses most/all of its magnetism quickly.
What is the magnetic field?
The region around a magnet where a force acts on another magnet or on a magnetic material (iron, steel, cobalt and nickel) is called the magnetic field.
What is the force between a magnet and a magnetic material?
The force between a magnet and a magnetic material is always one of attraction.
What does the strength of the magnetic field depend on?
The strength of the magnetic field depends on the distance from the magnet. The field is strongest at the poles of the magnet.
How is the direction of the magnetic field determined?
The direction of the magnetic field at any point is given by the direction of the force that would act on another north pole placed at that point. The direction of a magnetic field line is from the north
(seeking) pole of a magnet to the south(seeking) pole of the magnet.
What does a magnetic compass contain?
A magnetic compass contains a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the
Earth’s magnetic field.
What happens when a current flows through a conducting wire?
When a current flows through a conducting wire a magnetic field is produced around the wire. The strength of the magnetic field depends on the current through the wire and the distance from the wire
What does shaping a wire to form a solenoid do ?
Shaping a wire to form a solenoid increases the strength of the magnetic field created by a current through the wire. The magnetic field inside a solenoid is strong and uniform.
What is the shape of the magnetic field around a solenoid?
The magnetic field around a solenoid has a similar shape to that of a bar magnet. Adding an iron core increases the strength of the
magnetic field of a solenoid. An electromagnet is a solenoid with an iron core.
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. This is called the motor effect.
What is the basis of an electric motor?
A coil of wire carrying a current in a magnetic field tends to rotate. This is the basis of an electric motor
What is a solenoid?
a cylindrical coil of wire acting as a magnet when carrying electric current.
