16. A demultiplexer has ________.
(a) one data input and a number of selection inputs, and they have several outputs
(b) one input and one output
(c) several inputs and several outputs
(d) several inputs and one output
17. Which of the following is a semiconductor memory?
(a) RAM
(b) MAR
(c) CD-ROM
(d) CD
18. The holes through a PC board are ________.
(a) smaller with SMT than with through-hole mounting
(b) larger with SMT than with through-hole mounting
(c) the same size as with through-hole mounting
(d) usually unnecessary
19. A full subtracter circuit requires ________.
(a) two inputs and two outputs
(b) two inputs and three outputs
(c) three inputs and one output
(d) three inputs and two outputs
20. A flip-flop has ________.
(a) one stable state
(b) no stable states
(c) two stable states
(d) none of the above
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Introduction to Digital Systems » Exercise - 13. Digital systems represent quantities : (a) using more bits in its binary codes as the quantity value increases. (b) using more bits in its binary code as more accuracy is required. (c) using binary codes with just two levels – 1 or 0, high level or low level. (d) all of the above.- Introduction to Digital Systems » Exercise - 12. Analog signals : (a) vary smoothly, then change abruptly to new values. (b) consist of codes of high-level and low-level signals. (c) vary smoothly continuously. (d) have periods of high-level and low-level signals, then change to continuous signals.
- 555555555516. A demultiplexer has ________. (a) one data input and a number of selection inputs, and they have several outputs (b) one input and one output (c) several inputs and several outputs (d) several inputs and one output
- 555555555511. The output of an AND gate is LOW ________. (a) all the time (b) when any input is LOW (c) when any input is HIGH (d) when all inputs are HIGH
- 555555555512. The output of an OR gate is LOW when ________. (a) all inputs are LOW (b) any input is LOW (c) any input is HIGH (d) all inputs are HIGH