CK-12 Physical Science Concepts - For Middle School

http://www.ck12.org Chapter 5. Energy

FIGURE 5.186

This pinball machine uses several

solenoids to operate bumpers, switches,

and other moving parts.

Vocabulary

• solenoid: Coil of wire with electric current flowing through it, giving it a magnetic field like a bar magnet.

Explore More

At the following URL, explore the solenoid animation. Try varying the voltage and the direction of the current. Ob-
serve how these changes affect the magnetic field. Write a paragraph to summarize your observations. http://www.p
hysics-chemistry-interactive-flash-animation.com/electricity_electromagnetism_interactive/solenoid_magneticfield-
current_poles_north_south.htm

Review

1. Describe a solenoid and its magnetic field.


2. Which solenoid pictured below has a stronger magnetic field? How do you know?


3. How are solenoids used?