Electricity and Magnetism Flashcards
The places on a magnet where the magnetic forces are the strongest are called the…
poles
What is the definition of a magnetic field?
The area around a magnet where a force acts on another magnet or magnetic material
The area around a magnet where a force acts on another magnet or magnetic material in the…
Magnetic field
Two like poles always ______
repel
Tow opposite poles always _______
attract
What is a permanent magnet?
A magnet that produces its own magnetic field.
What is an induced magnet?
A magnetic material which becomes a magnet when placed in a magnetic field.
A magnetic material which becomes a magnet when placed in a magnetic field is a _______ _________
induced magnet
What type of magnet loses its magnetism when it is removed from a magnetic field?
induced magnet
Which three elements are magnetic?
iron, cobalt and nickel
Draw the magnetic field around a bar magnet
teacher to draw on board…
Give the name for the magnet created using a coil of wire
solenoid
Where is the strongest field in an electromganet created by a coil of wire?
inside the coil
What two words describe the magnetic field within the coil of a solenoid?
strong and uniform
What is an electromagnet?
A solenoid containing an iron core which increases its strength
What is an important property of a solenoid/electromagnet as a magnet
can be switched on and off with electric current
Flemming’s left hand rule shows the relative directions of what things?
Force, magnetic field and current
In Flemming’s LH rule, the thumb gives the direction of …
Force
In Flemming’s LH rule, the second finger gives the direction of …
Current
In Flemming’s LH rule, the first finger gives the direction of …
Magnetic Field
When a conductor carrying a current is placed in a magnetic field, the magnet and the conductor ….
exert an equal and opposit force on one another
Give three ways of increasing the force of a solenoid.
Add iron core, increase number of coils of wire, increase current, move magnetic material closer
Give three ways of increasing the force of a motor.
Increase the number of coils of wire, increase the strength of the magnetic field, increase the current
What is the unit of magnetic flux density?
Tesla (T)
What two methods can you use to obesrve the field around a bar magnet?
Iron filings or plotting compass
The right hand thumb rule shows relative direction of…
current and magnetic field around a wire
The strength of magnetic field surrounding a conducting wire depends on…
Size of current and distance from wire
State the equation which links current, force, length of conductor and magnetic flux density
F=BIl
Which rule can be used to determine the direction a motor will rotate?
Flemming’s left hand rule.
