Digital Electronics- Multivibrators and 555 Timer
Digital Electronics- Multivibrators and 555 Timer
11. What is the difference between an astable multivibrator and a monostable multivibrator?
- The astable is free running.
- The astable needs to be clocked.
- The monostable is free running.
- none of the above
12. Is there any limit to the number of times that a 74123 can be retriggered?
- TRUE
- FALSE
13. The output of the astable circuit ________.
- constantly switches between two states
- is LOW until a trigger is received
- is HIGH until a trigger is received
- floats until triggered
14. What controls the output pulse width of a one shot?
- the clock frequency
- the width of the clock pulse
- an RL time constant
- an RC time constant
16. 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 ________.
- value of the RC timing components
- amplitude of the input trigger
- frequency of the input trigger
- magnitude of the dc supply voltage
18. Triggering a retriggerable one shot during pulse generation will:
- time out the original pulse
- extend the pulse to this trigger width
- have no effect
- double the original pulse width
19. Triggering a retriggerable one shot during pulse generation will:
- time out the original pulse
- extend the pulse to this trigger width
- have no effect
- double the original pulse width
20. The monostable multivibrator circuit is not an oscillator because ________.
- its output switches between two states
- it requires a trigger to obtain an output signal
- it requires a sine wave input signal
- the circuit does not require a dc power supply