• Sara Thompson

Exciting Electromagnets

Electromagnet; Photo by Pearson Scott Foresman, on Wikimedia Commons

By Sara Thompson

Special to the Enterprise

Electromagnets can be found in a number of places, ranging from how a doorbell works all the way to helping particle accelerators perform their job. For something with so many applications an electromagnet has a very simple construction. An electromagnet is a magnet where the magnetic field is created by an electric current. To create an electromagnet, a wire is wound tightly around a metal core, and then connected to a source of electricity. This simple tool has almost countless applications and is used in many everyday things we may not think about.

In the 1820s, Hans Christian Oersted noticed his compass would act abnormally when a battery in his lab was switched on and return to normal when turned off and discovered that a magnetic field is generated by the battery. In 1824, William Sturgeon built the first electromagnet by wrapping copper wire around a horseshoe shaped piece of iron and connecting it to a battery. His electromagnet was able to attract other pieces of iron and demonstrated its magnetic force by lifting nine pounds with only his seven-ounce iron piece wrapped in wire. Ever since these breakthroughs, scientists have continued to study electricity, magnetism, and electromagnetism, and have continued to adapt the design to fit many aspects of modern life.

The core of an electromagnet is known as a solenoid. On its own it usually does not have an electric current, and the atoms in the object are oriented randomly. Once the coil is added and a current moves through it, the solenoid’s atoms realign and generate the magnetic field. Our homes and industry are full of electromagnets being found in something as mundane as a doorbell, where pushing the button completes the electric circuit and activates the clapper on the bell to the large magnets in junk yards that can lift cars are also electromagnets, allowing materials to lift objects much heavier than themselves. MRIs use electromagnets to generate the magnetic fields and waves that create the images doctor's view. Even large particle accelerators use electromagnets to control the particle’s trajectory and speed, so it doesn’t damage the machine.

Campers in this week’s Everyday Engineering camp made their own electromagnets with some wires, a small battery, and a nail. They also built buildings, cars, racetracks, and even a rocket from donated, recycled materials. Our after-school camps are current full but keep a lookout for more in the future. Camps will be Monday-Friday from 2:30-4:30pm for students in grades K-6. Price is $120 Members/$145 Non-Members. Additional information and registration can be found at https://www.explorit.org/camps.

Explorit's coming events:

• Due to COVID-19 restrictions and the health and safety of our staff and visitors, our gallery will remain closed. Staff regularly check messages and email.

• Like many small businesses the closures have had a significant impact on our income and sustainability. Now is a great time to donate and help Explorit continue to educate and inspire the scientists of tomorrow: https://www.explorit.org/donate.

• Continue to support Explorit during this uncertain time by becoming a member. An Exploit Membership not only support us but grants the recipient with free visits to Explorit’s regular public hours, discounts on events, summer and after-school camps, and workshops, and gives you ASTC benefits to visit other museums throughout the world. For more information visit https://www.explorit.org/membership or call Explorit at 530-756-0191.

Explorit is a non profit 503(c)(3) California Corporation founded in 1982

(530) 756-0191

3141 5th Street

Davis, CA 95618

Wednesday, 1pm - 5pm

Friday, 1pm - 5pm

Saturday & Sunday, 1pm - 5pm

$5 per person

Members - free admission

Children ages 2 & under - free

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