Electromagentic waves Flashcards
 How can a station broadcast music
by varying its carrier wave by modulating either its frequency or its altitude
how can you produce a carrier wave that goes up to 400 MHz
you use an oscillator with a capacitor and a coil connected in parallel
What are transmitters
Devices that converts music words pictures to electric signals and amplifies them then send them to an antenna
What does a receiver do
it splits the signals into a binary code to encode it and then the encoded signals become sound waves
 How does a radio broadcast
sound waves go into a microphone
Sound waves are changed into electromagnetic waves
They are then amplified and spread by an antenna
Antenna spreads out electric signals
Home radio uses its antenna to receive the electric signals by moving it’s receiver to a specific frequency
Electric signals are then turned into sound waves inside the radio

What kind of power do you need to have a changing magnetic field
The power source has to be alternating current
What is the antenna supposed to align with to catch the broadcasted signals
The Antinous to align with only the electric waves and parallel
What is a capacitor
An electric device used to store electrical energy made up of two conductors separated by insulator
What direction do the magnetic and electric field travel in
They travel right-angle to each other and perpendicular to the direction of the wave
What is the wavelength of electromagnetic wave in a vacuum
LINDA = c/f
what is the Wavelengths equation
LINDA = v/f
What is the electromagnetic radiation
It is the energy that is carried by electromagnetic wave
what is an antenna
It creates the electromagnetic waves the propagate through the air
What’s the dielectric
A poor conductor of electric current who is electric charges partly align with an electric field
What’s a carrier Wave
A specific wave length and the radio part of the electromagnetic spectrum that is assigned to a radio station
What are the three parts that a station broadcast information by using a transmitter
1.the oscillator generates the carrier wave
2.the modulator uses data to change the carrier waves amplitude or frequency
- the amplifier increases the potential difference of the resulting signal
How do you keep the oscillation study in coil and capacitive circuit
do use a transformer in order to get to the right frequency that will keep the isolation study for as long as possible
How do you produce waves with frequencies more than 400 MHz
by using a resonant cavity, I rectangular metal box that acts both as a coil and as a capacitor and its size determines the frequency of oscillation
How to produce waves with frequencies higher than 100 GHz
A resonant cavity would have to be reduced to a molecule size
What is Piezoelectricity
It’s the property when quartz crystals the form with a potential difference is applied across them, The application of an alternating current potential difference to the quarts Crystal will result in sustained oscillation
How are quartz used in electronegativity
Quartz crystals are commonly used to generate electromagnetic waves in electronics
Can an ant to know detect a Magnetic wave with a length that’s more than 1/2
Yes it can but I will be less efficient
How do you change between stations in a receiver
by adjusting the capacitance and the coil and capacitor circuit that’s in the receiver until the oscillation frequency of the circuit equals the frequency of the desired wave.you do that by using a tuner
