1.What is digital system?
Systems which process discrete values and digital values are called digital systems.
All discrete signals are digital signals but not all digital signals are discrete signals
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| Discrete signal |
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| Digital Signal |
2.What is analog system?
Systems which are capable of processing a continuous range of values varying with respect to time are called analog systems.
3.Difference between analog signal and digital signal.
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| Analog voltage vs time |
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| Digital voltage vs time |
Analog=continuous
Digital=Discrete(step by step)
4.Example for analog and digital system.
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Analog watch and digital watch.
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5. what are the advantages of digital system?
Exact value of voltage or current are not important.
Information storage is easy.
Accuracy and precision are greater.
Digital circuits are less affected by noise.
More digital circuitry can be fabricated on IC chips.
LOGIC GATES
6.What is logic gates?
A logic gate is an electronic circuit/device which makes the logical decisions(0 or 1). Logic gates have one or more inputs and only one output.
7.What are the most common logic gates?
OR(addition),AND(multiplication),NOT(inversion),NOR(inverse of OR),NAND(inverse of AND)
8.What are the universal gates? and Why?
NOR and NAND.All gates can be implemented by using universal gates.
9.Write are the symbols used for logic gates?
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| NOT |
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| AND |
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| OR |
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| NAND |
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| NOR |
10.What are the development stages of logic gates?
DRL(Diode-Resistor logic )->TTL (Transistor-Transistor logic)->CMOS(Complementary metal oxide semiconductor)
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| DRL |
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| TTL |
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| CMOS |
Fig. 2-input NAND gate
11.State Moore’s law?
"The number of transistors and resistors on a single chip will double every 18 months"
