Electromagnetism in Use Quick Check
What creates the magnetic force in an electromagnet?
1. coiled wire
2. electric current
3. iron or steel core
4. battery
Which statement about
electromagnets is correct?
1. Two south poles attract each
other.
2. A north pole and a south pole
attract each other.
3. Two north poles attract each
other.
4. A north pole and south pole repel
each other.
Which is the best description of how to build an electromagnet?
1. Wrap a wire around an iron or
steel core at least ten times.
2. Connect one end of a battery to an iron or steel core with a wire, then connect the other end of the battery to the core with another wire.
3. Attach a wire to one end of a battery, wrap the wire around an iron or steel core, and attach the other end of the wire to the other end of the battery.
4. Attach one end of a wire to a battery, and attach the other end of the wire to an iron or steel core.
What causes a maglev train to hover above the track?
1. repellant magnetic force
2. attractive magnetic force
3. electric current
4. massive batteries
1. repellant magnetic force
The answer to the first question is 2. electric current. The magnetic force in an electromagnet is created by the flow of electric current through a coiled wire.
The answer to the second question is 2. A north pole and a south pole attract each other. Opposite poles attract each other in electromagnets.
The answer to the third question is 3. Attach a wire to one end of a battery, wrap the wire around an iron or steel core, and attach the other end of the wire to the other end of the battery. This is the correct procedure to build an electromagnet.
The answer to the fourth question is 1. repellant magnetic force. A maglev train hovers above the track due to the repellant magnetic force between the magnets on the train and the magnets on the track.
To find the answer to the first question, "What creates the magnetic force in an electromagnet?" you can consider the basic principles of electromagnetism. An electromagnet is created by passing an electric current through a coil of wire, which in turn generates a magnetic field. So, the correct answer is 2. electric current.
For the second question, "Which statement about electromagnets is correct?" you can determine the correct statement by recalling the properties of magnets. Opposite poles attract each other, while similar poles repel each other. Therefore, the correct answer is 2. A north pole and a south pole attract each other.
To answer the third question, "Which is the best description of how to build an electromagnet?" you can analyze the options provided. Building an electromagnet involves wrapping a wire around an iron or steel core and passing an electric current through it. Based on the options, the correct description is 3. Attach a wire to one end of a battery, wrap the wire around an iron or steel core, and attach the other end of the wire to the other end of the battery.
Lastly, for the question "What causes a maglev train to hover above the track?" you need to recall the principle behind magnetic levitation. Maglev trains use repelling magnetic forces to levitate above the track and move forward. Therefore, the correct answer is 1. repellant magnetic force.