Multiple choice

The circuit diagram of a standard TTL NOT gate is shown in the figure. When Vi = 2.5 V, the modes of operation of the transistors will be

  1. Q1 : reverse active; Q2 : normal active; Q3 : saturation; Q4 : cut-off

  2. Q1 : reverse active; Q2 : saturation; Q3 : saturation; Q4 : cut-off

  3. Q1 : normal active; Q2 : cut-off; Q3 : cut-off; Q4 : saturation

  4. Q1 : saturation; Q2 : saturation;Q3 : saturation; Q4 : normal active

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation