Electromagnetism question (specifically receivers)

In summary: EM field of the waves in the vicinity of the antenna are what stimulates the receiver to amplify the signal.
  • #1
revv
55
9
I have trouble understanding how a receiver doesn't get bombarded with frequencies... and exactly how does a receiver only "accept" certain frequencies?

I understand if you send energy(or electricity) through a copper wire (and other types of metals) it makes a frequency with certain hertz (correct me if I am wrong please)

I might be completely interpreting everything I just said wrong but hopefully it makes sense.

thank you for taking the time to read and reply to me
 
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  • #2
If you stick a wire up in the air, all the passing Radio Frequency signals will add up to induce a small voltage to appear at the output lead. The function of a Radio Receiver is that it filters out all those signals that it doeans't want and only amplifies the band of frequencies that the wanted signal occupies. When you 'tune' a receiver, you are adjusting the filter frequency so you pick up only the signal you want. It is always possible that there will be interference in the wanted channel when there is another station on the same frequency.
 
  • #3
Thank you again for taking the time to reply to me sophie I really appreciate it. I will try to read more about this I still don't quite understand but if I ever have more questions I will come back to this thread!
 
  • #5
revv said:
I understand if you send energy(or electricity) through a copper wire (and other types of metals) it makes a frequency with certain hertz (correct me if I am wrong please)

not quite

The copper wire is just that, a bit of wire.
it's the AC/RF generator attached to the wire, that is supplying the energy at a specific frequency
 
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  • #6
davenn said:
t's the AC/RF generator attached to the wire, that is supplying the energy at a specific frequency
Or the EM fields of the waves in the vicinity of the wire.
 
  • #7
sophiecentaur said:
Or the EM fields of the waves in the vicinity of the wire.

yup, for the receive situation
 

What is the difference between an electromagnet and a permanent magnet?

Electromagnets are created by passing an electric current through a coil of wire, while permanent magnets are made from materials with naturally occurring magnetic properties. Electromagnets can be turned on and off by controlling the electric current, whereas permanent magnets always have a magnetic field.

How do electromagnetic receivers work?

Electromagnetic receivers use a combination of antennas, amplifiers, and filters to receive and interpret electromagnetic waves. The antenna captures the waves and sends them to the amplifier, which boosts the signal. The filter then separates the desired signal from any other interference, allowing the receiver to detect and interpret the information being transmitted.

What is the relationship between frequency and wavelength in electromagnetism?

Frequency and wavelength are inversely proportional in electromagnetism, meaning that as the frequency increases, the wavelength decreases and vice versa. This relationship is described by the equation: wavelength = speed of light / frequency.

What are some common uses for electromagnetic receivers?

Electromagnetic receivers have a wide range of applications, including radio and television broadcasting, wireless communication, radar and sonar systems, GPS navigation, and medical imaging. They are also used in scientific research to study and measure the properties of electromagnetic waves.

How does the strength of an electromagnetic field affect the performance of a receiver?

The strength of an electromagnetic field can have a significant impact on the performance of a receiver. A stronger field can provide a clearer and more reliable signal, while a weaker field may result in a weaker or distorted signal. The distance between the receiver and the source of the electromagnetic waves also plays a role in the strength of the field and the performance of the receiver.

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