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  • Question
  • When the inputs to a flip-flop are changing at the same time that the active trigger edge of the input clock is making its transition, this condition is called:


  • Options
  • A. racing
  • B. toggling
  • C. slave loading
  • D. pulse timing

  • Correct Answer
  • racing 


  • Digital Design problems


    Search Results


    • 1. One example for the use of a Schmitt trigger is as a(n):

    • Options
    • A. switch debouncer
    • B. racer
    • C. astable oscillator
    • D. transition pulse generator
    • Discuss
    • 2. The output of a standard TTL NAND gate is used to pull an LED indicator LOW. The LED is in series with a 470-Ω resistor. What is the current in the circuit when the LED is on?

    • Options
    • A. 7.02 mA
    • B. 8.51 mA
    • C. 10.63 mA
    • D. 5.32 mA
    • Discuss
    • 3. The ________ circuit overcomes the problem of switching caused by jitter on the inputs.

    • Options
    • A. astable multivibrator
    • B. monostable multivibrator
    • C. bistable multivibrator
    • D. Schmitt trigger
    • Discuss
    • 4. What is the major advantage of the J-K flip-flop over the S-R flip-flop?

    • Options
    • A. The J-K flip-flop is much faster.
    • B. The J-K flip-flop does not have propagation delay problems.
    • C. The J-K flip-flop has a toggle state.
    • D. The J-K flip-flop has two outputs.
    • Discuss
    • 5. The main concern when using a pull-down resistor is:

    • Options
    • A. the low power dissipation of the resistor
    • B. it will keep a floating terminal LOW
    • C. the high power dissipation of the resistor
    • D. it will cause false triggering
    • Discuss
    • 6. If Vcc of a 555 timer circuit is set to +10 V what is the level of output voltage from the circuit?

    • Options
    • A. VOH = 10 V, VOL = 0 V
    • B. VOH = 10 V, VOL = 0.1 V
    • C. VOH = 8.5 V, VOL = 0 V
    • D. VOH = 8.5 V, VOL = 0.1 V
    • Discuss
    • 7. In a typical IC monostable multivibrator circuit, at the falling edge of the trigger input, the output switches HIGH for a period of time determined by the ________.

    • Options
    • A. value of the RC timing components
    • B. amplitude of the input trigger
    • C. frequency of the input trigger
    • D. magnitude of the dc supply voltage
    • Discuss
    • 8. If a diode is connected across resistor RB (positive end up) in the given figure, what is the new duty cycle of the output waveform?


    • Options
    • A. 56%
    • B. 44%
    • C. 21.6%
    • D. 17.4%
    • Discuss
    • 9. To obtain a 50% duty cycle in an astable 555 timer circuit:

    • Options
    • A. tLO = tHI
    • B. RA = RB and short RB with a diode during the capacitor charging cycle
    • C. capacitor voltage must rise above 1/3 VCC
    • D. tLO = tHI, RA = RB, and short RB with a diode during the capacitor charging cycle
    • Discuss
    • 10. An astable multivibrator requires:

    • Options
    • A. balanced time constants
    • B. a pair of matched transistors
    • C. no input signal
    • D. dual J-K flip-flops
    • Discuss


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