Lic theory

What is the function of the comparators in the 555 timer circuit?

• to compare the output voltages to the internal voltage divider

• to compare the input voltages to the internal voltage divider

• to compare the output voltages to the external voltage divider

• to compare the input voltages to the external voltage divider

When capacitor charges

• the voltage across the plates rises exponentially

• the circuit current falls exponentially

• the capacitor charges to the source voltage in 5×RC seconds

• All of the above

Pulse stretching, time-delay, and pulse generation are all easily accomplished with which type of multivibrator circuit?

• Bistable

• Monostable

• Multi stable

• Astable

The internal circuitry of the 555 timer consists of ________, an R-S flip-flop, a transistor switch, an output buffer amplifier, and a voltage divider.

• A comparator

• A voltage amplifier

• Two comparator

• Peak detector

With most monostable multivibrators, what is the Q output when no input trigger has occurred?

• Low

• +5v

• Set

• High

With most monostable multivibrators, what is the Q output when no input trigger has occurred?

• Balanced time constant

• Pair of matched transistors

• No input signal

• Dual j k flipflop

What is the difference between an astable multivibrator and a monostable multivibrator?

• The unstable is free running

• The Astable is free running

• Monostable is free running

• Need a clock pulse

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

A monostable 555 timer has the following number of stable states:

• 0

• 1

• 2

• 3

What is another name for a bistable multivibrator?

• Turn on off switch

• Flip flop

• oscillator

• None of these