WorksheetsMaglev Trains , Electromagnets, Magnets
Total questions: 19
Worksheet time: 19mins
Magnetic field lines go from ____________ to ____________ outside a magnet.
north to south
south to north
positive to negative
left to right
Magnetic fields are created by:
Stationary electric charges only
Only bar magnets
Moving electric charges and magnetic materials
Sunlight hitting metal
What happens to a magnetic field if the current in an electromagnet is reversed?
It disappears
The magnetic field gets stronger
The direction of the magnetic field reverses
Nothing changes
Why do magnetic field lines never cross?
They are just drawings and don’t matter
They represent the temperature of magnets
A magnetic field can only have one direction at a point in space
They’re blocked by electric fields
What strengthens an electromagnet?
Decreasing the number of coils
Wrapping wire into a straight line
Adding an iron core and more current
Using fewer electrons
What allows maglev trains to move without touching the track?
Wheels with magnets
Magnetic levitation from repelling forces
Compressed air under the train
Rocket boosters
Which is NOT an advantage of maglev trains?
Less noise
Lower friction
Use of fossil fuels
Smoother rides
What makes maglev systems expensive to build?
Train drivers earn high salaries
The train cars are heavier
Special tracks and strong magnets are costly
They need water cooling systems
How do engineers control the speed of maglev trains?
By adjusting fuel levels
By reversing and changing the strength of magnetic fields
By rotating the wheels faster
By adding more train cars
Which of the following is always magnetic and does not require electricity?
Electromagnet
Permanent magnet
Magnetic coil
Battery
What do electromagnets need in order to work?
Sunlight
Gravity
Electricity
Water
Which of the following is a feature of electromagnets?
Always on
Strength cannot change
Can be turned on and off
Made only of neodymium
What would make an electromagnet stronger?
Using fewer coils
Lowering the current
Using plastic instead of metal
Adding more coils and increasing the current
Why are electromagnets useful in machines like junkyard cranes?
They are lightweight
They can be turned off to drop heavy objects
They never lose magnetism
They don't use electricity
Why don't we use electromagnets in compasses?
They are too weak
They use too much power
Their magnetic field might interfere with direction
They're not made of iron
Which of these is an example of a permanent magnet?
Car battery
Magnetic crane
Compass needle
Magnetic door lock
What happens to the magnetic field of an electromagnet when the current is turned off?
It becomes stronger
It reverses
It disappears
It spreads
What does wrapping a wire into a coil do to the magnetic field?
Weakens it
Makes it invisible
Strengthens it
Reverses its direction
Why are electromagnets used in maglev trains?
They are cheaper than permanent magnets
They create less heat
Their strength and direction can be changed quickly
They never lose power
