Digital Electronics-Flips-Flops

Digital Electronics-Flips-Flops
21. A J-K flip-flop is in a "no change" condition when ________.
  • J = 1, K = 1
  • J = 1, K = 0
  • J = 0, K = 1
  • J = 0, K = 0
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22. A correct output is achieved from a master-slave J-K flip-flop only if its inputs are stable while the:
  • clock is LOW
  • slave is transferring
  • flip-flop is reset
  • clock is HIGH
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23. Which of the following describes the operation of a positive edge-triggered D flip-flop?
  • If both inputs are HIGH, the output will toggle.
  • The output will follow the input on the leading edge of the clock.
  • When both inputs are LOW, an invalid state exists
  • The input is toggled into the flip-flop on the leading edge of the clock and is passed to the output on the trailing edge of the clock.
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24. What does the triangle on the clock input of a J-K flip-flop mean?
  • level enabled
  • edge-triggered
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25. A J-K flip-flop with J = 1 and K = 1 has a 20 kHz clock input. The Q output is ________.
  • constantly LOW
  • constantly HIGH
  • a 20 kHz square wave
  • a 10 kHz square wave
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26. The toggle condition in a master-slave J-K flip-flop means that Q and will switch to their ________ state(s) at the ________.
  • opposite, active clock edge
  • inverted, positive clock edge
  • quiescent, negative clock edge
  • reset, synchronous clock edge
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27. On a positive edge-triggered S-R flip-flop, the outputs reflect the input condition when ________.
  • the clock pulse is LOW
  • the clock pulse is HIGH
  • the clock pulse transitions from LOW to HIGH
  • the clock pulse transitions from HIGH to LOW
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28. What is the hold condition of a flip-flop?
  • both S and R inputs activated
  • no active S or R input
  • only S is active
  • only R is active
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29. If an active-HIGH S-R latch has a 0 on the S input and a 1 on the R input and then the R input goes to 0, the latch will be ________.
  • SET
  • RESET
  • clear
  • invalid
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30. In VHDL, how many inputs will a primitive JK flip-flop have?
  • 2
  • 3
  • 4
  • 5
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