logo

CuriousTab

CuriousTab

Discussion


Home Digital Electronics Multivibrators and 555 Timer Comments

  • Question
  • A 22-kΩ resistor and a 0.02-µF capacitor are connected in series to a 5-V source. How long will it take the capacitor to charge to 3.4 V?


  • Options
  • A. 0.44 ms
  • B. 0.501 ms
  • C. 0.66 ms
  • D. 0.70 ms

  • Correct Answer
  • 0.501 ms 


  • Multivibrators and 555 Timer problems


    Search Results


    • 1. Is the circuit given below an astable multivibrator or a monostable multivibrator?


    • Options
    • A. monostable
    • B. astable
    • Discuss
    • 2. What is the function of the comparators in the 555 timer circuit?

    • Options
    • A. to compare the output voltages to the internal voltage divider
    • B. to compare the input voltages to the internal voltage divider
    • C. to compare the output voltages to the external voltage divider
    • D. to compare the input voltages to the external voltage divider
    • Discuss
    • 3. The ________ is defined as the time the output is active divided by the total period of the output signal.

    • Options
    • A. on time
    • B. off time
    • C. duty cycle
    • D. active ratio
    • Discuss
    • 4. If the resistor in the Schmitt trigger astable multivibrator is a variable resistor, what part of the output voltage waveform will change when the resistance is changed?

    • Options
    • A. the shape of the waveform
    • B. the amplitude of the waveform
    • C. the period of the waveform
    • D. none of the above
    • Discuss
    • 5. Which mode of operation is being used when a 555 timer chip has two external resistors and an external capacitor?

    • Options
    • A. monostable
    • B. pulse stretching
    • C. Schmitt triggering
    • D. astable
    • Discuss
    • 6. Triggering a retriggerable one shot during pulse generation will:

    • Options
    • A. time out the original pulse
    • B. extend the pulse to this trigger width
    • C. have no effect
    • D. double the original pulse width
    • Discuss
    • 7. The monostable multivibrator circuit is not an oscillator because ________.

    • Options
    • A. its output switches between two states
    • B. it requires a trigger to obtain an output signal
    • C. it requires a sine wave input signal
    • D. the circuit does not require a dc power supply
    • Discuss
    • 8. Does the 74123 one shot have an internal timing resistor?

    • Options
    • A. yes
    • B. no
    • Discuss
    • 9. What does the discharge transistor do in the 555 timer circuit?

    • Options
    • A. charge the external capacitor to stop the timing
    • B. charge the external capacitor to start the timing over again
    • C. discharge the external capacitor to stop the timing
    • D. discharge the external capacitor to start the timing over again
    • Discuss
    • 10. What controls the output pulse width of a one shot?

    • Options
    • A. the clock frequency
    • B. the width of the clock pulse
    • C. an RL time constant
    • D. an RC time constant
    • Discuss


    Comments

    There are no comments.

Enter a new Comment