Virtual Labs

To design a delay timer circuit using 555 timer IC.

The internal circuitry of the 555 Timer IC consists of ______, an RS flip flop, a transistor switch, an output buffer amplifier and a voltage divider.

a: A comparator b: A voltage amplifier c: Two comparators d: A peak detector

What is the function of the comparator in the 555 Timer circuit?

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

What does the discharge transistor do in the 555 Timer circuit?

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

What controls the output pulse width of a one shot?

a: The clock frequency b: The width of the clock pulse c: An RL time constant d: An RC time constant

A retriggerable one shot has a pulse of 10 ms. 3 ms after being triggered, another trigger pulse is applied. The resulting output pulse will be _____ ms.

a: 3 b: 7 c: 10 d: 13

What is the difference between a retriggerable one shot and a non-retriggerable one shot?

a: The non-retriggerable can only be triggered once b: The retriggerable can be triggered many times c: The output pulse can be stretched with a non retriggerable d: The output pulse can be stretched with a retriggerale

Which mode of operation is being used when a 555 Timer chip has two external resistors and an external capacitor?

a: Monostable b: Pulse stretching c: Schmitt triggering d: Astable

The frequency of operation of an astable multivibrator using 555 Timer IC is given by

a: 0.724/RC b: 1.38RC c: 0.69RC d: RC/0.724

In an astable multivibrator using 555 Timer IC the capacitor always charge between

a: 0 and Vcc b: 0 and 2/3 Vcc c: 1/3 Vcc and 2/3 Vcc d: None

With reference to astable mode of operation of 555 Timer IC which one of the following statements is true?

a: Trigger terminal is always shorted to the threshold terminal b: Reset terminal is always grounded c: Reset terminal is always at Vcc d: Trigger terminal is left open