A Demonstration of Lenz’s Law (1835)

Prepared by Mark Spencer WA8SME

Lenz’s Law (1835)

• Anytime and electron moves…it creates a magnetic field

• Anytime a magnetic field moves or changes…it caused electrons to move

Plastic/Copper/Aluminum

• Plastic – Fast

• Copper – Slowest

• Al - Medium

• Insulator – no moving electrons therefore no magnetic field created

• Conductor – opposing magnetic field created from moving electrons

• Cu is better conductor than Al – more moving electrons, stronger magnetic field

Falling Magnet and Radio Waves• Transmitter

– Moves electrons in the antenna in step with intelligence to be sent

– Moving electrons create magnetic field

– Changing magnetic field creates electrostatic field (moving electrons)

– Repeats and spreads out at about the speed of light• Alternating magnetic-

electrostatic fields (electro-magnetic radiation)

• Receiver– The final magnetic field

washes across the receiving antenna

– Causes electrons to move in the antenna and down the coax to the receiver

– Receiver extracts the intelligence

• THE MAGIC OF RADIO