Questions & Answers of Frequency response of amplifiers

•  (A) The device parasitic capacitances behave like open circuits, whereas coupling and bypass capacitances behave like short circuits.
•  (B) The device parasitic capacitances, coupling capacitances and bypass capacitances behave like open circuits.
•  (C) The device parasitic capacitances, coupling capacitances and bypass capacitances behave like short circuits.
•  (D) The device parasitic capacitances behave like short circuits, whereas coupling and bypass capacitances behave like open circuits.

The ac schematic of an NMOS common-source stage is shown in the figure below, where part of the biasing circuits has been omitted for simplicity. For the n -channel MOSFET M, the transconductance g_m = 1 mA/V, and body effect and channel length modulation effect are to be neglected. The lower cutoff frequency in Hz of the circuit is approximately at

•  (A) 8
•  (B) 32
•  (C) 50
•  (D) 200