Question

16. Compared to bipolar junction transistors, field effect transistors are NOT normally characterized by (a) low input impedance. (b) low power consumption. (c) high input impedance. a reverse-biased pn junction.

Answer 1

Comparision between BIT & FET :- 1. BIT is current controlled device while FET has voltage based device 2. BTT has Three Terminals devices Terminals named as emitter, base, Collector, Fet is also a three Terminal device named as source, gate, drain, 3. in BJT Emilter & collector is not insterchangable while in RET, source & drain are Interchanable. 4. FET can be made gcúte small as compared to BTT 5, BTT is more noisy than FET due to its Junction → compared to BJT's, fet are not characterized by, Ans: (a). low input Impedence is correct r. FET offers grater in put impedence than BTT's. which is severale Thousand's of obro's, (with such high input impedence, The FET practically draws no current to its input gate Terminal. Therefore, since practically no current is drawn from the power supply circuít, The powerp Supply Circuit is not loaded down. & RET Trans Eslor circuits are well isolated. Therefore better power control is achieved with peris)

(6): low power consumption is wrong AFET is low power consumption' as compared with Boy 21: high input impedence is wrong =FET baving high input impedence compared with BJT because it is voltage controlled device. [d]. A reverse bias pr Junction 13 wrong. It is high reverse bias pie Junction at Drain & lower reverse bias at source Terminal. This bias cause's deplétion layer to be formed with in the channel & whose width is increses with bias as compared with BIT'S