P7 AI Flashcards
What are the two types of poles in all magnets?
North (or north seeking) pole and south (or south seeking) pole.
What happens when like poles of two magnets are brought close together?
They repel each other.
What happens when unlike poles of two magnets are brought close together?
They attract each other.
Fill in the blank: Objects don’t need to be touching for a _______ to act between them.
non-contact force.
What materials are considered magnetic materials?
- Iron
- Steel
- Nickel
- Cobalt
What is the magnetic field of a magnet?
The area around a magnet where it can exert a force.
How can magnetic fields be visually represented?
With magnetic field lines.
Which direction do magnetic field lines go?
From north to south.
What does it mean if magnetic field lines are closer together?
A stronger magnetic field.
Where is the magnetic field strongest in a magnet?
At the poles.
What is the function of a compass needle?
It points in the direction of any magnetic field.
What happens to a compass when it is not near a magnet?
It always points north.
Why does a compass point north?
Because it points in the direction of the Earth’s magnetic field.
What are permanent magnets?
Magnets that create their own magnetic field.
What is an induced magnet?
A magnet that turns into a magnet when it’s put into another magnetic field.
What happens to induced magnets when the magnetic field is removed?
They quickly stop being magnets.
True or False: Permanent magnets and induced magnets always attract each other.
True.
Complete the analogy: Magnets are like _______ — surrounded by fields.
farmers.
What is found around a wire that has a current passing through it?
A magnetic field
A magnetic field is generated when current flows through the wire.
What does a current flowing through a wire create?
A magnetic field
This can be observed by using a compass.
How can you visualize the magnetic field around a current-carrying wire?
By placing a compass near the wire
The compass will point in the direction of the magnetic field.
What shape is the magnetic field around a wire?
Circles around the wire
The field lines form concentric circles.
What is the Right-Hand Thumb Rule used for?
To determine the direction of the magnetic field
Point your right thumb in the direction of current and curl your fingers.
What happens to the direction of the magnetic field when the current direction is reversed?
The direction of the magnetic field is reversed
Swapping the current direction changes the field direction.
How does distance from the wire affect the strength of the magnetic field?
The closer you are to the wire, the stronger the magnetic field
The strength diminishes with distance.
What effect does increasing the current have on the magnetic field?
It increases the strength of the magnetic field
More current leads to a stronger magnetic field.
What is a solenoid?
A coil of wire
It is formed by wrapping a wire into a coil.
What is the characteristic of the magnetic field inside a solenoid?
Strong and uniform
Uniform means the field has the same strength and direction everywhere.
What happens to the magnetic field outside a solenoid?
It resembles the magnetic field around a bar magnet
The field lines outside a solenoid are similar to those of a magnet.
How does wrapping wire into a solenoid affect the magnetic field?
It increases the strength of the magnetic field
Field lines around each loop align, strengthening the overall field.
What can be added to a solenoid to further increase the magnetic field strength?
A block of iron
An iron core enhances the magnetic field in the solenoid.
What is a solenoid with an iron core called?
An electromagnet
The iron core significantly increases the strength of the magnetic field.
True or False: A magnetic field is created by a current-carrying wire.
True
The relationship between current and magnetic fields is a fundamental principle of electromagnetism.
Fill in the blank: The direction of the magnetic field can be determined using the _______.
Right-Hand Thumb Rule
This rule helps visualize the relationship between current direction and magnetic field direction.
What is meant by a magnetic field being ‘uniform’?
The field has the same strength and direction everywhere
This is a key characteristic of the field inside a solenoid.
True or false? The force between a north pole and a south pole is attractive.
True
True or false? A magnet always repels a magnetic material.
False
In what direction do magnetic field lines point?
From north to south
How can you draw a magnetic field pattern of a bar magnet using a compass?
By placing the compass around the magnet and tracing the direction of the needle
Describe the behaviour of a compass that is far away from any magnets.
It points toward the Earth’s magnetic north
Explain how to use the right-hand thumb rule to find the direction of a magnetic field around a wire.
Point your right thumb in the direction of current flow; your fingers curl in the direction of the magnetic field lines
What is a solenoid?
A coil of wire that produces a magnetic field when an electric current passes through it
Sketch the shape of the magnetic field around a solenoid.
The field lines are similar to those of a bar magnet, with lines emerging from one end and looping around to the other
How can you increase the strength of a solenoid’s magnetic field?
By increasing the current, adding more turns to the coil, or using a ferromagnetic core
