Information Technologies and Instrumentation Study Guide

Question 1

Electric Telegraph (Morse Code)

no electric or sound energy involved.

Answer 1

• is an old form of communication is most known for its use in transmitting morse code in the early 1800s.
• in a telegraph, the electric current is sent as signals through a wire to a receiving end. the signals, which are morse code, at the receiving end have to be decoded.
• morse code: an alphabet or code in which letters are represented by combinations of long and short dingal of light or sound when used with the telegraph

Question 2

Alexander Graham Bell (telephone)

Answer 2

• In 1876, Alexander Graham Bell eliminated the need for decoding by the receiver by inventing the telephone.
• the telephone operates by converting sound energy from the transmitter into electric energy as it travels through a wire and back to sound energy at the receiving end.

Question 3

Wavelength v. Frequency

Answer 3

Wavelength and frequency are inversely related to each other.

Question 4

Mechanical wave vs. Non-Mechanical Wave

Answer 4

• Mechanical waves require a medium to travel through and transfers energy through a medium
• This is why we can’t hear anything in space, there is no air for sound to move through… ex: water ripples
• Non-Mechanical waves do not require a medium to travel through.
• This is why radio waves and microwaves can pass through the Earth’s atmosphere and travel in space… ex: light waves

Question 5

Radio waves

are they mechanical or non-mechanical?

Answer 5

• radio waves are non-mechanical waves that are generated by vibrating electrons
• the longest wavelength on the em spectrum and the lowest frequency.
• televisions, phones, and radio signal

Question 6

Lasers

what do they produce? how can they be transferred?

Answer 6

• lasers produce a narrow beam of coherent light waves
• can be efficiently transferred from one place to another by using fiber optics.

Question 7

Coherent light

Answer 7

• Coherent light waves are waves that follow a similar pattern, or are waves that are in sync. (Incoherent light is the opposite)

Question 8

Fiber optics

what are the benefits to fiber optics?

Answer 8

• is a flexible, transparent fiber made of glass or plastic.
• are so small that they are usually bundled into fiber optic cables. because they can be bundled, a higher volume of information can be transmitted.
• is used for long-distance data transfers– the biggest use for fiber optics are the internet

Question 9

Internal reflection

Has to do with optical fibers, what does internal reflection do?

hint: reflection

Answer 9

• inernal reflection are waves inside an optical fiber that reflect throughout the fibers
• therefore, the data transmitted remains high quality even over long distances.

Question 10

Electromagnetic Spectrum

Answer 10

• Radio waves have the lowest frequency and energy, longest wavelength. Televisions and radio signals are transmitted through radio waves
• Microwaves have higher frequencies and shorter wavelengths than radio waves. Microwaves are used to heat up your food as well as radar.
• Infrared has shorter wavelengths than microwaves and higher frequencies. Infrared means “below red.” Infrared is used in thermograms or thermal imaging and remote controls. Part of the mid-range.
• Visible light is the only type of electromagnetic radiation that we can see. The waves have shorter wavelengths and higher frequencies than infrared. It is the narrowest part of the EM spectrum. Part of the mid-range.
• Ultraviolet rays have shorter wavelengths and higher frequencies than visible light. Ultraviolet means “above violet.” Ultraviolet light is often used in medical practices and is the radiation from the sun that we shield ourselves from using sunscreen. Part of the mid-range
• X-rays have shorter wavelengths than ultraviolet rays and higher frequencies. X-rays can pass through some forms of matter such as skin but it cannot penetrate through bone due to its density. It is absorbed instead.
• Gamma rays have the shortest wavelengths and the highest frequencies of any other type of radiation on the EM spectrum which means they have the highest energy. They are dangerous but also in treating some types of cancer

Question 11

Electromagnetic waves & communication benefits

what speed do EW travel at? how have EW waves helped w/ communication?

Answer 11

• Electromagnetic waves do not need a medium to travel through. therefore they are non-mechanical and can travel through any empty space.
• EM waves are good for communication because they travel from one place to another very quickly, at the speed of 300,000,000m/s.
• Examples of how EM waves has provided communication benefits: telephone poles, walkie talkies, cellphones, computers and satellites.

Question 12

why is digital communication is important?

how we stay connected to ___?

Answer 12

is important because it is vital to how we communicate with others around the world, and how we stay connected to those we love. Digital communication allows people to chat online, enable collaboration, allows people to stay in touch, exchange knowledge and ideas. Without digital communication, many people would lose contact with their family members that are across the world.

Question 13

Describe the advantages and disadvantages of digital communication compared to older forms of communication such as the telegraph.

Answer 13

• There are many advantages and disadvantages of digital communication compared to older forms of communication such as the telegraph.
• Digital communication has significantly changed our world because it allows people to connect with others online.
• Older forms of communication, such as the telegraph, are more outdated and do not give the same benefits as digital communication.
• However, the telegraph transmits information across large distances. Digital communication also does not work without wifi or data.