Question

Transistors are commonly used in digital circuits as electronic switches which can be either in an "ON" / "OFF" State. For transistor working as a
Switch, which of the following analogy is true;
Answer Your Question
(a) Both junctions reverse bias::OFF conditions;
АО;
(b) Junction 1 is Forward bias, Junction 2 is Reverse bias::ON condition:
BO;
(c) Both junctions forward bias::OFF condition
CO;
D (d) None of these​

Answer 1

Answer:

With a zero signal applied to the Base of the transistor it turns “OFF” acting like an open switch and zero collector current flows. With a positive signal applied to the Base of the transistor it turns “ON” acting like a closed switch and maximum circuit current flows through the device.