Permanent Magnets
Temporary Magnets
Circuits
Labs, Activities & Authentic Examples
IV, DV, Constant
100
Draw and label 2 permanent magnets that ATTRACT
N-S
100
List the parts that you need to build an electromagnet
Battery (or source), wire coil, and an iron core.
100
What is OHM'S LAW equation? Also show what each letter in the equation stands for.
OHM'S LAW: I = V/R I=current V=voltage R=resistance
100
In Investigation 10.1, students "tested" items around the classroom to see if they attracted, repelled, or had no effect. List at least 3 types of materials that attract or repel (which materials are natural magnets?)
Iron, steel, cobalt and nickel
100
Define INDEPENDENT VARIABLE
Independent Variable is what is changed on purpose in an experiment.
200
Draw and label 2 permanent magnets that REPEL
N-N or S-S
200
List at least 2 ways to increase the strength of an electromagnet.
-Increase the number of wire coils -Increase the voltage -Increase the amount of iron in the core
200
How are CURRENT and RESISTANCE related to each other? Hint: if one increases/decreases, what happens to the other?/
Current and Resistance have an "inverse relationship." As resistance increases, current decreases.
200
In Investigation 10.1, students used a metric ruler to measure the distance that permanent magnets attract or repel to each other. Based on your results, were the distances similar or significantly different for the distance to attract and repel. Explain your answer.
The distances were similar, they were NOT significantly different. They were about the SAME distance. For example, the average distance to attract and repel was between 42.5 mm and 48.5 mm.
200
Define DEPENDENT VARIABLE
Dependent Variable is what is measured in an experiment.
300
What will happen if you break a permanent magnet in half? Explain your answer.
If you break a permanent magnet in half, you will have two smaller permanent magnet. You can not split up the NORTH and SOUTH poles in a permanent magnet.
300
Describe 2 ways in which an electromagnet is SIMILAR to a permanent magnet.
-Both attract/repel to IRON/STEEL, COBALT, NICKEL -Both have a North and South pole -Both have a magnetic field
300
Explain one way to DECREASE resistance in a circuit.
-use a shorter wire -use a thicker wire
300
In the Electromagnet Investigation, some students did not have success in attracting any paper clips. Describe one problem that those students could have experienced.
-The exposed copper wire was not connected to the battery holder wires -There was no voltage from the battery -The wire coils were not touching the iron core
300
Identify the IV from the following example: Mike and Jess build an electromagnet in science class using a 3-volt battery, a nail and some wire. They wrap the nail with 10, 20, then 30 coils. They try to pick up paper clips with magnetic attraction.
IV = 10, 20 or 30 coils
400
Describe how the atoms are arranged in a peice of magnetized IRON.
In a peice of iron, the atoms are all arranged facing in the same direction. This makes all IRON have a North and South pole. Atoms in other (non-magnet) materials are arranged in a random pattern.
400
Describe one specific way in which electromagnets are used in every day life.
Electromagnets are used to turn on/off things such as doorbells, automatic door locks, recylcling machines, metal sorting at junk yards, etc.
400
Solve the following problem. Show all work and include units. How much VOLTAGE is needed in a circuit that has 12 amps of current and 3 ohms of resistance?
V =I x R V= 36 volts
400
How does a compass work? Explain.
A small, thin peice of iron rests on a friction-less surface. The peice of iron points towards the NORTH because it experiences magnetic force from the Earth's poles.
400
Identify the Dependent Variable from the following example: Mike and Jess build an electromagnet in science class. They use a 3-volt battery, some wire and an iron nail. They use 10, 20 and 30 coils. They try to pick up paper clips by magnetic attraction.
DV = the number of paper clips picked up
500
How is a permanent magnet DIFFERENT than an electromagnet? List at least 2 ways.
-Electromagnets can be turned on/off, permanent magnets cannot. -Electromagnets can increase/decrease strenght, permanent magnets cannot. -Electromagnets use current, permanent magnets do not.
500
Explain how to tell the North/South pole for an electromagnet. Be specific.
Electromagnets North and South poles are found using the "Right Hand Rule." This rule says that if you wrap the fingers of your right hand in the same direction as the wire coils, your thumb will point to the North pole of the magnet.
500
Define both word: INSULATORS and CONDUCTORS. Give one example of each.
Electrical Insulators do not allow current to travel through. Example: rubber, plastic, foam, wood, glass, etc. Electrical Conductors do allow current to travel through. Example: metals, water.
500
If your job was a TOY MANUFACTURER, would you build toys for small children/babies that were made from magnets? Explain your position.
PRO: magnets would help small children build objects (such as towers, etc) because the parts could attract to each other. CON: if children accidentally swallowed several magnets, they could attract to each other inside the body. This could cause pain and damage to internal organs if the magnets are strong enough to attract to each other.
500
Define and Identify the CONSTANT in the following example: Mike and Jess build an electromagnet in science class. They use a 3-volt battery, a wire and an iron core. They use 10, 20 and 30 coils. They try to pick up paper clips by using magnetic attraction.
Definition: Constant is something that stays the same in an experiment. Answer: Constant could include: same voltage battery, same type of wire, same type of nail, wrap the wire in the same direction.
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