Magnetism & Electromagnetism

Unit 5.2 Magnetism and Electromagnetism Research Project

Scientists

Joseph Henry

1. The focus of his research was electricity.

2. Henry aided Samuel F.B. Morse in developing the telegraph and discovered principles of electricity, including self-induction.

3. When he was working with electromagnets at the Albany Academy in New York in 1829, he made design improvements which included an electromagnet by insulating the wire instead of the iron core, and increased the power of the magnet.

4. He came up with the process of converting magnetism into electricity. Henry discovered that currents could be induced at a distance, and magnetized a needle by utilizing a lightening flash eighty miles away. He also devised and constructed the first electric motor. In 1831 Henry built and successfully operated a telegraph he designed.

5. Modern uses of Henry’s research are the telegraph. He first used radio waves across a distance and that’s still used today.


Nikola Telsa


1. Nikola Tesla focused on electricity such as free electricity.

2. Tesla discovered a way to transmit electricity -- alternating current (AC), and ways to use magnetic fields. He also developed the three-phase system of electric power transmission and he invented the Tesla coil, an induction coil widely used in radio and television technology.

3. His works included work with a carbon button lamp, various types of electricity, and the power of electrical resonance. Also he invented the telautomatic boat guided by a remote control.

4. Modern uses of Telsa’s inventions and discoveries are things such as the Tesla coil, remote control boats, alternating currents, and the radio.

"Conte Alessandro Volta." Britannica School. Encyclopædia Britannica, Inc., 2013. Web.

20 Mar. 2013. <http://school-preview.eb.com/levels/high/article/75699>.


Motors and Generators

How is electromagnetic induction used with motors and generators?

For starters the production of emfs and currents by the changing magnetic field through a conducting loop is called induction.

The crank represents a mechanical method of turning the loop of wire in a magnetic field. The change in magnetic flux through the loop generates an induced current; thus, the generator converts mechanical energy into electrical energy. The operation of a motor is similar to that of a generator but in reverse. The motor has similar physical components except that the electric current supplied to the loop exerts a torque, which turns the loop. The motor, therefore, converts electrical energy into mechanical energy.

CliffsNotes.com. Electromagnetic Induction. 4 Apr 2013

<http://www.cliffsnotes.com/study_guide/topicArticleId-10453,articleId-10436.html>.


Electromagnetism in life : Telephone

When you speak to a friend through the telephone, your sound will be converted into electric current by the mouthpiece of the telephone. The current produced is a varying current and the frequency of the current will be the same as the frequency of your sound. The current will be sent to the earpiece of the telephone of your friend.
When the current passes through the solenoid, the iron core is magnetised. The strength of the magnetic field changes according to the varying current. When the current is high, the magnetic field will become stronger and when the current is low, the magnetic field become weaker.The soft-iron diaphragm is pulled by the electromagnet and vibrates at the frequency of the varying current. The air around the diaphragm is stretched and compressed and produces sound wave. The frequency of the sound produced in the telephone earpiece will be the same as your sound. Telephones have greatly improved our lives. They have advanced communication and the speed of communicating with others, far and near.

"SPM Physics Form 5 - Electromagnetism: Uses of Electromagnet - Telephone Earpiece." SPM Physics Form 5 - Electromagnetism: Uses of Electromagnet - Telephone Earpiece. N.p., n.d. Web. 04 Apr. 2013. <http://physics503.one-school.net/2008/06/uses-of-electromagnet-telephone.html>.

Electromagnetism in life : Computers

Computers are an example of how humans use electromagnets to improve our lives.When you save data to the hard drive in your computer, for example, tiny, magnetized pieces of metal are embedded onto a disk in a pattern specific to the saved information. This data started life as binary digital computer language (0s and 1s). When you retrieve this information, the pattern is converted into the original binary pattern and translated into a usable form. The electrical force running through the computer’s circuitry magnetizes those tiny bits of metal. Computers have advanced technology and Humans use computers daily. They have improved our lives through quick and easy acces to the internet, and writing documents. Computers have also helped with communication among people everywhere who also have internet.

Brain, Marshall, and Lance Looper. "How Electromagnets Work" 01 April 2000. HowStuffWorks.com. <http://www.howstuffworks.com/electromagnet.htm> 04 April 2013.

Phone picture taken by; Isabella B.

Computer picture taken by: Clarke M.

Electromagnetism in life : speaker

When the electrical field flowing through the voice coil changes direction, the coil's polar orientation reverses.the voice coil is a basic electromagnet. An electromagnet is a coil of wire, usually wrapped around a piece of magnetic metal, such as iron. Running the electrical current through the wire creates a magnetic force around the coil, magnetizing the metal it is wrapped around. A speaker constantly reverses the flow of electricity. If you've ever hooked up a stereo system, then you know that there are two output wires for each speaker -- typically a black one and a red one. Essentially, the amplifier is constantly switching the electrical signal, fluctuating between a positive charge and a negative charge on the red wire. Since electrons always flow in the same direction between positively charged particles and negatively charged particles, the current going through the speaker moves one way and then reverses and flows the other way. This alternating current causes the polar orientation of the electromagnet to reverse itself many times a second.

Harris, Tom. "How Speakers Work" 02 February 2001. HowStuffWorks.com. <http://electronics.howstuffworks.com/speaker.htm> 04 April 2013

Electromagnetism in Life: Toaster


The latch release in the toaster is held shut by an electromagnet.

In modern toasters this is achieved by driving the electromagnet with a timing circuit . The timing circuit stays live until a capacitor reaches maximum charge, and then as the current dies, the magnetic field dies and the electromagnet releases the toast carriage, which is returned by a spring to eject the toast.

In older toasters, the electromagnet current was released by the motion of a bimetallic strip breaking the current.

Brain, Marshall. "How Toasters Work" 03 May 2000. HowStuffWorks.com. <http://home.howstuffworks.com/toaster.htm> 04 April 2013.


Toaster picture taken by: Clarke M.







Electromagnetism in Life: Printer

Many computer printers rely on electromagnets to power their motors, the same power that printer's moving parts use. These motors are known as stepper motors, and many other common electronics, such as fax machines and disk drives. A single stepper motor contains several stationary electromagnets known as the stator, which surrounds a rotating, permanent magnet, known as the rotor. In order to generate power, the motor conducts an electrical current into only one electromagnet at a time. As each electromagnet activates, it pulls the rotor towards it.


Devaney, Erik. "What Home Appliances Use Electromagnets?" EHow. Demand Media, 01 Sept. 2010. Web. 04 Apr. 2013. <http://www.ehow.com/list_7179595_home-appliances-use-electromagnets_.html>.



Printer Picture taken by: Isabella B.



Bibliography

Devaney, Erik. "What Home Appliances Use Electromagnets?" EHow. Demand Media, 01

Sept. 2010. Web. 04 Apr. 2013. <http://www.ehow.com/list_7179595_home-appliances-

use-electromagnets_.html>.

Brain, Marshall. "How Toasters Work" 03 May 2000. HowStuffWorks.com. <http://home.howstuffworks.com/toaster.htm> 04 April 2013.

Harris, Tom. "How Speakers Work" 02 February 2001. HowStuffWorks.com. <http://electronics.howstuffworks.com/speaker.htm> 04 April 2013

Brain, Marshall, and Lance Looper. "How Electromagnets Work" 01 April 2000. HowStuffWorks.com. <http://www.howstuffworks.com/electromagnet.htm> 04 April 2013.

"SPM Physics Form 5 - Electromagnetism: Uses of Electromagnet - Telephone Earpiece." SPM Physics Form 5 - Electromagnetism: Uses of Electromagnet - Telephone Earpiece. N.p., n.d. Web. 04 Apr. 2013. <http://physics503.one-school.net/2008/06/uses-of-electromagnet-telephone.html>.


CliffsNotes.com. Electromagnetic Induction. 4 Apr 2013

<http://www.cliffsnotes.com/study_guide/topicArticleId-10453,articleId-10436.html>.



"Conte Alessandro Volta." Britannica School. Encyclopædia Britannica, Inc., 2013. Web.

20 Mar. 2013. <http://school-preview.eb.com/levels/high/article/75699>.