what is magnetism???
DESCRIPTION
What is Magnetism???. Hmmm…. Magnetism – A force of attraction and repulsion. Law of Magnetic Poles. N. S. Magnetic Field. Magnetic Domains. Demagnetizing a Magnet. 1) Heating. 2) Dropping. 3) Other Strong Impact. Electricity and Magnetism. ?. - PowerPoint PPT PresentationTRANSCRIPT
What is Magnetism???Hmmm…
Magnetism – A force of attraction and repulsion
Law of Magnetic Poles
N S
Magnetic Field
Magnetic Domains
Demagnetizing a Magnet
1) Heating
2) Dropping
3) Other Strong Impact
So, can an ordinary nail become a magnet?
Nail
Wire wrapped around nail
Paperclips attracted to the nail
Electromagnet
Predicting the Factors Affecting Electromagnet Strength
Increasing # Coils
Decreasing # Coils
Increasing Power
Decreasing Power
Increasing Core Diameter
Decreasing Core Diameter
Factors Affecting Electromagnet Strength
Battery Strength
+ Iron Nail with 40 Coils
# Paper Clips
# Coils + Iron Nail
+ 6V Battery
# Paper Clips
Diameter of Core + 40 Coils +
6 V Battery
# Paper Clips
9 V 5
AA 10
C 25
6 V 50
Generators• Turns mechanical energy into electrical energy
A wire turns within a magnet creating an electrical current
Which is stronger???
A B
A B
Which is stronger???
Part I –Electromagnets and Communication
Today’s wireless communication devices – smart phones, Ipods, email, etc. all owe their existance to the invention of the telegraph in the 1830’s.Using an electromagnet and wires connecting the transmitter and receiver, messages could be sent over long distances using Morse Code, a system of communication long used with flags and lights.
Today you will be constructing your own telegraph system. You will be working together to construct an electromagnet transmitter/receiver.
Look at the pictures and think about the material you are provided. Be sure to think about what materials conduct electricity and what materials are magnetic. Then build your own transmitter/receiver.
Part II –Morse Code
Initially developed in 1836, Morse Code was used for the transmission of words prior to the invention of voice communication (i.e. telephone).It is based on a series of dits (•) and dahs (-) based on how often each letter occurs in English words.
Part II –Morse Code
For many years, telegraph stations connection railway station via wires and were used to transmit information about train schedules, news, and “wire” money.
Part II –Morse Code
With the advent of wireless telegraphs, Morse code also became the standard form of communication between ships and airplanes, replacing semaphore.
Part II –Morse Code
After constructing your telegraph system, you will be sending your partner a message using Morse code.
Write a message in English. Using the following code key, translate the message to Morse code. Practice using the transmitter until you are able to send your message.
Your partner will be receiving and decoding your message. Your partner will then send you a message to decode.
Morse Code