Test: Frequency Response - Electronics and Communication Engineering (ECE) MCQ

G iven for an FET, g_m = - 9 .5 m A /volt, total capacitance = 500 pF. For a voltage gain of -30, the bandwidth will be

The drain gate capacitance of a junction FET is 2 pF. Assuming a common source voltage gain of 20, what is the input capacitance due to miller effect?

Assertion (A): In the high frequency model of FET, the voltage amplification drops drastically with increase in frequency.
Reason (R): The high frequency model is identical with the low frequency model except that the capacitances between various terminals (gate, source and drain) is added.

For a single stage CE amplifier, g_m = 50 mA/V, C_e= 1 pF and C_c = 0.2 pF. The frequency at which the short circuit common-emitter current gain attains unit magnitude is given by

When the load resistance is zero (short circuit) in a common-emitter configuration, the current flowing from the base to the collector node through the collector capacitor C_c, is small because

Consider the following statements:
1. For finding the transistor behaviour at high frequency it is necessary to examine the diffusion mechanism.
2. At low frequency it is assumed that the transistor responds instantly to changes of input voltage or current.
3. The hybrid-jr model is valid under dynamic conditions when the rate of change of \/BEis small enough so that the base incremental current/^ is small compared with the collector incremental current/^
4. The parameter fTis a frequency characteristic of a transistor.

Which of the above statements are correct?

A modern bipolar transistor can have C_e = 1 pF. If g_m = 50 mA/V, the f_T of a common emitter amplifier will be