Discovery of Electromagnetism an Accidental Discovery Electricity And

We made the simple device in this picture for physics class. We wrapped a wire around a nail and connected the ends of the wire to the terminals of a battery. The nail is attracting paper clips, so it appears to have become magnetised. The device isn’t complicated, but it shows a very important relationship.

An accidental discovery

The discovery of the relationship between magnetism and electricity was, like so many other scientific discoveries, stumbled upon almost by accident. The Danish physicist Hans Christian Oersted was lecturing one day in 1820 on the possibility of electricity and magnetism being related to one another, and in the process demonstrated it conclusively by experiment in front of his whole class! By passing an electric current through a metal wire suspended above a magnetic compass, Oersted was able to produce a definite motion of the compass needle in response to the current. What began as conjecture at the start of the class session was confirmed as fact at the end. Needless to say, Oersted had to revise his lecture notes for future classes! His serendipitous discovery paved the way for a whole new branch of science: electromagnetics.

Electricity and Magnetism

Magnetism produced by electricity is called electromagnetism. Christian Oersted made the important discovery that electric current creates a magnetic field.After his discovery, Oersted wanted to learn more about the magnetic field created by a current. He placed a compass at different locations around a wire with current flowing through it. You can see what he found in the Figure below. The lines of magnetic force circle around the wire in a counterclockwise direction. Review

1. What observation led Oersted to conclude that electricity and magnetism are related? 2. How did Oersted ﬁnd the direction of the magnetic ﬁeld around a wire carrying current?

What Do You Think?

Learn more about Oersted and electromagnetism at the links below. Then answer the questions that follow.

• http://www.famousscientists.org/hans-christian-oersted/ • http://www.school-for-champions.com/science/electromagnetic_devices.htm • https://youtu.be/Cz7V7QoD1LA

1. How did Oersted discover electromagnetism? 2. How does the demonstration in the video above relate to Oersted’s discovery? 3. How did Oersted’s discovery inﬂuence the history of science? 4. What are three useful characteristics of electromagnets that permanent magnets do not have? 5. Give an example of a device that makes use of each of the characteristics you identiﬁed in your answer to question 2. 6. What do you think? How might your life be different without Oersted’s lucky discovery?

Answer to this questions, save the answers on a ﬁle in pdf format and submit it in google classroom. Discovery of Electromagnetism Practice Worksheet

Visit CK12.org for Free Online Practice

True False Questions

Indicate True or False for the following Statements.

1. Oersted’s discovery took years of careful scientiﬁc investigation. (True/False )

2. Prior to Oersted’s discovery, scientists thought that electricity and magnetism were unrelated. (True/False )

3. Oersted demonstrated that the lines of magnetic force circle around a wire in a counterclockwise direction. (True/False )

Short Answer Questions

4. Who discovered that a magnetic ﬁeld can generate electric current?

5. Who concluded that electricity and magnetism are related?

Fill in the Blanks Questions

Fill in the answer blanks with correct answer.

6. Oersted found the direction of the magnetic ﬁeld around a wire carrying current by placing a ______in many places around the wire.

7. The process by which a magnetic ﬁeld produces current is electromagnetic ______.

8. Faraday discovered that a magnetic ﬁeld can produce an electric ______.

9. Electromagnetic induction occurs when a ______crosses lines of force in a magnetic ﬁeld.

10. Oersted made the discovery that electric current creates a magnetic ______.