06_INTRODUCTION TO ELEC COM_PART 1 Flashcards
(31 cards)
What is communication?
The basic process of exchanging information
Most humans communicate through the spoken word, but a considerable amount of communication is nonverbal.
What are the two major barriers in human communication?
- Language
- Distance
What year did Professor Joseph Henry transmit the first practical electrical signal?
1830
Who invented the telegraph?
Samuel Morse
What significant invention did Alexander Graham Bell and Thomas A. Watson create in 1876?
The telephone
Who discovered radio waves in 1887?
Heinrich Hertz
What major milestone in communications occurred in 1901?
The first transatlantic transmission of radio signals by Guglielmo Marconi
What is defined as the transmission, reception, and processing of information using electronic circuits?
Electronic Communications
What are the basic elements of a communication system?
- Transmitter
- Communications channel or medium
- Receiver
What is the difference between analog and digital signals?
- Analog signals: continuously changing with infinite amplitude values
- Digital signals: discrete with finite amplitude values
What components make up a transmitter?
- Amplifier
- Modulator
- Oscillator
- Antenna
What are the two general types of communications media?
- Guided (wired)
- Unguided (wireless)
What is noise in the context of communication systems?
Any unwanted form of energy that interferes with the reception and reproduction of desired signals
Define bandwidth in communication systems.
The portion of the electromagnetic spectrum occupied by a signal or the frequency range over which an information signal is transmitted
What is Hartley’s Law?
States that information capacity is directly proportional to bandwidth and transmission time
What are the two modes of transmission in electronic communications?
- One-way (simplex)
- Two-way (duplex)
What is simplex communication?
One-way communication, also known as broadcasting
What is half-duplex communication?
A type of two-way communication where only one party can transmit at a time
What is full-duplex communication?
A type of two-way communication where both parties can transmit and receive simultaneously
What does the electromagnetic frequency spectrum refer to?
The entire range of usable frequencies, extending from a few Hz to cosmic rays
What is frequency measured in?
Hertz (Hz)
What frequency range is designated as ELF?
30 – 300 Hz
What is the frequency range for Voice Frequencies (VF)?
0.3 – 3 kHz
What is the major application of Medium Frequencies (MF)?
AM Radio broadcasting (535 – 1605 kHz)
