Electric Forces
Magnetic Forces
Mixed Bag 1
Electromagnetism 1
Electromagnetism 2
Mixed Bag 2
100
A negatively charge object and positively charged object will ___________ .
attract
100
True or False? The magnetic domain is the area around a magnet where the magnetic force acts.
False - magnetic field
100
This material easily allows electrons to flow through it.
conductive material / conductor
100
What is the main advantage of using an electromagnet?
The ability to turn it on and off.
100
This is the area around a magnet where the force is exerted.
magnetic field
100
When a current flows through a wire, this is produced.
magnetic field
200
As the amount of charge in either of the two objects increases, the electric force between them __________.
increases
200
Like poles of a magnet will ....
repel
200
Plastic, wood, rubber, and glass are examples of ______________ which means they do not allow electrons to easily pass.
insulators
200
This rotates within an electric motor.
coils of copper wire
200
This is a conductive wire wrapped around an iron core or other ferromagnetic material an attached to a source of energy.
electromagnet
200
In order to be magnetic an object must have all of these aligned to face the same direction.
magnetic domains
300
If the distance between two charge objects increases, what effect will it have on the strength of the electric force?
The strength of the electric force decreases
300
These are groups of atoms which have aligned themselves to all face in the same direction.
magnetic domains
300
What is the main difference between and open and closed circuit?
An open circuit has a switch.
300
Magnetism produced by electric current is known as this.
What is electromagnetism?
300
A device that changes mechanical energy into electrical energy via electromagnetic induction is known as this.
generator
300
This is a device that uses an electromagnet to convert electrical energy into mechanical energy.
electric motor
400
True or False? When the amount of positive charge on an object equals the amount of negative charge on an object, the object is electrically neutral.
True
400
The are of a magnet where the force is the strongest
The poles / North Pole / South Pole
400
To construct an electromagnet you need an iron core, a power source, and ________.
conductive wire
400
Which of the following describes both an electromagnet and a permanent magnet?
A. The poles can be reversed.
B. The strength of the magnetic force can be controlled.
C. The magnetic force can be turned off and on.
D. It has a north pole and a south pole.
D. It has a north pole and a south pole.
400
To increase the electric current in a motor or electromagnet one must...
increase voltage
400
As a nail approaches the south pole of a magnet, what happens to its magnetic domains?
The north poles of the domains point toward the magnet.
500
A student runs a plastic ruler through a piece of wool 5 times to make the ruler electrically charged. The student then places the rule above bits of paper and counts how many pieces of paper it was able to pick up. Next the student runs the ruler though the pice of wool 15 times and records how many pieces of paper it could pick up. What question is the student likely trying to investigate?
Does adding more charge to an object increase the electric force?
500
Is this piece of iron going to act as a magnet?
No
500
When a wire is exposed to a changing (rotating) magnetic field, this is produced.
electrical current
500
During an investigation, a teacher places a small permanent magnet with a hole in it onto a wooden rod. The magnet can slide freely up and down the rod. When the teacher places the magnet and rod on a tabletop above an electromagnet, the magnet slides up the rod as shown in the diagram.
A student measures how far the magnet slides up the rod each time the teacher adds an additional battery to the electromagnet.
Which question could most likely be answered by this investigation?
How does the amount of the electric current affect the distance the magnet travels up the rod?
Reason: The amount or magnitude of the electric current affects the strength of the magnetic field of the electromagnet.
500
These are the three ways to increase the strength of an electromagnet.
1. increasing the number of turns in the coil
2. Adding an iron core / using a larger iron core
3. increasing the amount of current / increasing voltage
500
Seki wants to build a tread mill that is connected to a small generator that would power a phone charger. She is worried that just walking would not create a strong enough current to power a phone for long. What could she do to increase the current? Explain.
1. She could run instead of walk. Running would make the generator turn faster which would generate more current in less time.
2. She could increase the number of loops in the coil.
600
A class or 8th grade students have created their own electromagnets in their groups. Each group recorded a different number of paper clips their electromagnet was able to pick up. What is at least one question you could ask the class to help the groups understand the difference in their results?
1. How many loops / turns does your electromagnet have?
2. How many batteries are connected to your electromagnet? / How much voltage
600
A group of students make an electromagnet for a lab. They add 12 loops to their coil and record the number of staples it can pick up. The group takes away 2 coils and tests the electromagnet again. They repeat these steps until there are only 2 loops left. What is the independent variable of this experiment? What is the dependent variable?
independent variable - the number of loops
dependent variable - the number of staples picked up