Meliora (4.4) 1

Name: ______________________________

Class: _______________________________

Activator: 4.4 – Electromagnets 2 Date: _______________________________

Directions:

Place your science binder on your desk and login to Quizlet. Use Quizlet to review the vocabulary terms. You may

use ANY of the learning tools on Quizlet, including the games, to help you practice the vocabulary. Remember, you

will have a vocabulary pop quiz at some point this week. In the space below this paragraph, write “I read all of the

directions.” By doing so within the first two minutes of class, you will earn an easy 100% on your activator. You do

not need to answer the “How are you feeling today?” question unless you want to.

HOW ARE YOU FEELING TODAY?

Meliora (4.4) 2

Name: ______________________________

Class: _______________________________

Exit Ticket: 4.4 – Electromagnets 2 Date: _______________________________

On a scale of 1 to 10, how well did you understand the material in today’s class? Write your answer in the box to the right. (1=I understood nothing at all, 10=I understand the material so well I could teach it tomorrow)

1. Which of these is not something necessary for building an electromagnet? (Circle your choice)

a. b. c. d.

2. How does an electromagnet work?

a. Moving electrons create an electric field.

b. Moving electrons create a magnetic field.

c. A moving magnet creates an electric field.

d. A moving magnet creates a magnetic field.

3. Which of these could NOT be used to build an electromagnet?

a. Iron

b. Nickel

c. Copper

d. Carbon

4. Angel built an electromagnet. What will happen to the electromagnet when the battery dies?

a. The magnetic field will stay the same.

b. The magnetic field will decrease.

c. The magnetic field will increase.

d. The magnetic field will disappear.

5. If Angel wants to increase the power of the electromagnet, what should she do?

a. Lay the wire flat

b. Stretch the wire out as much as possible

c. Create an open circuit

d. Coil the wire as much as she can

Is there anything you want Mr. Buresh to know?

Meliora (4.4) 3

Name: ______________________________

Class: _______________________________

Classwork: 4.4 – Electromagnets 2 Date: _______________________________

OBJECTIVE: IWBAT explain ways to increase the strength of an electromagnetic to examine the effects of

changing an electromagnets structure.

Solenoid

A ____________________________ is a coil of wire that produces a magnetic field when carrying an

______________________ current.

Electromagnet

A ________________ that is made by passing an electric current

through a __________________ (in the form of a solenoid) wrapped

around an __________________________ core is called an

electromagnet.

While current flows, the core behaves like a

__________________________.

But, as soon as the _______________________ __________, the

magnetic properties are _________!

Meliora (4.4) 4

Magnetic Field of an Electromagnet

That magnetic __________________ produced around the wire is similar to that surrounding a

____________ magnet.

The magnetic ___________ pole is where the current (abbreviated by ____) goes in and the magnetic

north pole is where it exits in the wire coil.

Just like all magnets, the direction of the field still moves from ________ to ________________

Draw an electromagnet and its magnetic field:

Ways to Strengthen an Electromagnet

Four ways to strengthen an electromagnet:

o Increasing the ________________________ running through the solenoid (which can be done by

increasing the _________________________ of the electrical source).

o Placing an ____________ core at the _____________________ of the coil.

o Increasing the number of __________ of the wire or solenoid

o Increasing the ____________________ of the wire coil.

Advantages of Electromagnet

Electromagnets are very useful because they can be _____________________ _______ and ________ as

needed. The solenoid has a field only when there is electric current in it.

Electromagnets are also very useful to ___________________ ___________________________ (north

pole becomes south pole, etc.).

The ________________ of an electromagnet can be ___________________ by changing the battery or the

number of loops around the core to strengthen or weaken it.

Meliora (4.4) 5

Practice 1: Activity: Illustrate It!

Design your own electromagnet below. Make sure to include the following: Battery, Iron or steel core, copper wire. Once done, label all the parts.

Making a Magnetic Field (Circle the correct answer below, and fill out the missing terms)

1. If you sprinkle iron filings around a piece of copper wire, a magnetic field APPEARS/DOES NOT APPEAR.

2. If you run a current in the copper wire, a magnetic field APPEARS/DOES NOT APPEAR.

3. The field around one wire is WEAK/STRONG.

4. The field around a tight coil of wire is WEAK/STRONG.

5. One way to make the field stronger is to wrap the wire around an iron nail – this creates a

________________________________.

6. An electromagnet is a TEMPORARY/PERMANENT magnet – it only has magnetic force when an electric

current passes through the wire. If you turn the electricity off, the magnet no longer works. How might you

use this property to make a useful tool?

______________________________________________________________________________________

______________________________________________________________________________________

Controlling Electromagnets 7. There are four ways to make an electromagnet stronger:

a. _______________________________________________________________________________

b. _______________________________________________________________________________

c. _______________________________________________________________________________

d. _______________________________________________________________________________

8. You are creating your own electromagnet! Put the following events in order from step 1-5.

______ Connect the ends of the wire to a battery in a battery holder.

______ Use the electromagnet to lift 25 paper clips.

______ Wrap an iron nail with a length of copper wire.

______ Use the electromagnet to lift 12 paper clips.

______ Add twice as many coils of wire to the electromagnet.

Meliora (4.4) 6

Use the following description to answer questions 9 - 12

The Electromagnet A has 5 loops and Electromagnet B has 10 loops. Both electromagnets have the same thickness of copper wire and strength of battery. Furthermore, both electromagnets have identical iron nails as the core.

9. Which electromagnet is stronger? How do you know?

10. What would happen to Electromagnet A if you added another battery? Why?

11. What would happen to Electromagnet B if the battery was removed? Why?

12. If you replaced the nail with a piece of plastic, do you think the electromagnet would be stronger or weaker? Why?

Practice 2:

1. A diagram is shown below. What device is the diagram representing? _____________________

2. Label each part of the diagram above. Be sure to label all three parts

3. What are the ways to increase the strength of an electromagnet?

______________________________________________________________________________________

______________________________________________________________________________________

______________________________________________________________________________________

______________________________________________________________________________________

Meliora (4.4) 7

4. Which materials would be BEST to use as the core of an electromagnet?

______________________________________________________________________________________

5. How does an electromagnet differ from a regular magnet?

______________________________________________________________________________________

______________________________________________________________________________________

6. How would you compare the magnetic field generated by a simple length of wire to the magnetic field

generated by a coil of wire?

______________________________________________________________________________________

______________________________________________________________________________________

7. How might an electric motor be used in a washing machine?

______________________________________________________________________________________

8. Which of the following would increase the strength of an electromagnet?

a. Using more nails

b. Making more loops with the wire

c. Flipping the battery upside down

d. Adding a switch

9.

Meliora (4.4) 8