Waves pt 2

Question 1

Endoscopes

Answer 1

It is a device that is used to look inside the body without having to perform open surgery.

Question 2

How are Endoscopes used

Answer 2

Lenses are used at both ends, a tiny objective lens at the distal tip focuses an image onto cut ends of the optical fibres of the main bundle. Each fibre of the bundle collects and carries the light for one pixel of the image. An eyepiece lens at the operator end takes light exiting from the fibre bundle and refocuses it to be viewed as an image by the eye or camera.

Question 3

Are Endoscopes Analogue or Digital

Answer 3

Endoscopes are Analogue. This is because the brightness and colour of each pixel vary with time in direct proportion to the light collected by objective lens.

Question 4

Analogue

Answer 4

A signal may either mimic the variation in size and quality of the physical quantity it represents.

Question 5

Digital

Answer 5

It can encode information as series of numbers.

Question 6

Inverse square law

Answer 6

It shows us the intensity of the light to an observer from a source is inversely proportional to the square of the distance from the observer to the source.
I = k/r^2.
I = light intensity (w/m^2)
K = constant 
r = distance from light sources (m)

Question 7

Intensity

Answer 7

It is the strength of an electromagnetic wave which depends on the distance the wave travels. Meaning that the signal is weaker when the signal has to travel further. Devices that communicate over longer ranges need to emit stronger.

Question 8

Advantages of Digital

Answer 8

• More data fitted in the same bandwidth.
• Most interference can be eliminated giving higher quality.
• Information can be easily stored and edited by computers
• Can not be tapped/hacked
• sends large amount of information at one time.

Question 9

Properties of Analogue

Answer 9

• Low quality (Quality)
• Noise or interference is amplified (Interreference)
• high loss of signal strength (Attenuation)
• sends small amount of information at one time (Amount of information transmitted)
• Difficult to store on computers as large spaced
  used (Computer usage)
• Quite easy to tap/hack (Security)

Question 10

Mobile phone signal

Answer 10

• They use Microwaves.
• The devices it communicates between are Mobile phone to telephone.
• They can communicate between more than one device at once.
• It needs to send the signal at a distance of a few km.
• The Mobile phones strength of signal it emits is high.
• And it can travel through walls.

Question 11

Bluetooth

Answer 11

• They use UHF radio waves.
• The devices it communicates between are device to device (mobile to mobile).
• They can not communicate between more than one device at once.
• It needs to send the signal at a distance of 5m
• It’s strength of signal it emits is low.
• And it can not travel through walls.

Question 12

WIFI

Answer 12

• They use UHF radio waves.
• The devices it communicates between are device to multiple devices (mobile to printer).
• They can communicate between more than one device at once.
• It needs to send the signal at a distance of 10m
• It’s strength of signal it emits is in the middle.
• And it can travel through walls.

Question 13

Satellite communications

Answer 13

• They use Microwaves.
• The devices it communicates between mobile phone to satellite.
• They can communicate between more than one device at once.
• It needs to send the signal at a distance of many km .
• It’s strength of signal it emits is high.
• And it can travel through walls.

Question 14

Infrared

Answer 14

• They use Infrared waves.
• The devices it communicates between device to device (remote to TV)
• They can not communicate between more than one device at once.
• It needs to send the signal at a distance of about 1m.
• It’s strength of signal it emits is low.
• And it can not travel through walls.