Flashcards
Chapter 2 - Signalling Flash Cards
Flashcards do conjunto (16)
- 1Whats the difference between a digital signal and an analogue signal1. A digital signal is represented by binary numbers - 0 and 1.
2. An analogue signal can take any value - 2What is sampling?Sampling is the process in which the displacement of a an analogue system is measured at small time intervals and turned into a digital signal
- 3If a sample is coded with 4 bits, what is the maximum number of quantisation levels available? What would be highest signal value?The highest signal value would be (111) for a 3 bit coding - so 7
- 4What is meant by quantisation error?The difference between the signal value and the quantisation level
- 5What two factors can you adjust to improve the quality of the digitised signal?Improve:
a) The resolution
b) The sampling rate - 6What is the definition of a resolution of a sample?The resolution of a sample is the smallest change in p.d that can be measured
- 7What is the formula for resolution?
- 8When a sample has noise, increasing the number of quantisation levels will simply sample the noise instead of ignoring it. What is the formula for the maximum useful number of levels?
- 9What is the sampling rate?The number of samples taken each second
- 10What could happen if you sample too slowly?1) High frequency detail will be missed
2) Low frequency signals called aliases can be produced - 11What must the minimum sampling rate be larger than?Minimum sampling rate > 2 x maximum frequency of signal
- 12What is the definition of Bit Rate?The rate of transmission of digital information
- 13What is the formula for the bit rate?
- 14What is the formula for the duration of a signal?
- 15List the advantages of using digital signals.1. Digital signals do not suffer as much as analogue signals from noise
2. Digital signals can be compressed
3. Digital Signals are easier to send, receive and reproduce
4. Computers can easily process digital signals. - 16List the disadvantages of digital signals.1. Can never reproduce analogue signals exactly
2. Digital signals can be reproduced illegally
3. Confidential information can be stolen.
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- A-Level Physics FlashCards sobre Chapter 2 - Signalling Flash Cards, criado por Kavinda J.D em 04-09-2016.
- Criado por
- Kavinda J.D
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