Question

Phase shift provided by overall tank circuit is ___________

(a) 0 degree

(b) 90 degree

(c) 180 degree

(d) -90 degree

I got this question by my college director while I was bunking the class.

I'd like to ask this question from Colpitts Oscillator-2 in chapter Oscillators of Analog Circuits

Answer 1

Right option is (c) 180 degree

Explanation: The overall phase shift provided by tank circuit is 180 degrees. Since the active element produces a phase shift of 180 degrees the tank circuit should create 180 degrees to obey Barkhausen’s criteria.