(a) write the functions of the three segments of a transistor.
(b) The figure shows the input weveforms A and B for 'AND' gate Draw the output
waveform and write the truth table for this logic gate
.

Explanation

(a) A junction transistor is obtained by growing a thin layer of one type semi conductor in
between two thick layers of other similar type semi conductor.
Three layers and functions:
(i) Emitter (E) : The left hend side thick layer of the transistor which is heavily doped
It emits the majority carrier.
(ii) Base (B) : It is a central thin layer of the transistor which lightly doped . Correlates
interaction between emitter and collector.
(iii) Collector (C) : The right hand side thick layer of the transistor which is moderately
doped . It collects the majority carrier.
(b) See Q . 12 (i) , Set - III Delhi Board - 2009.