Electronics (ECE) - MCQ Practice Questions

The bandwidth of a common emitter amplifier can be increased by

In a differential amplifier, the common mode rejection ratio (CMRR) is defined as

The input impedance of a voltage follower (common collector) amplifier is

At what frequency does the gain of a RC coupled amplifier reduce to 70.7% of its mid-band gain?

In an RC coupled amplifier, the lower cutoff frequency is primarily determined by

For a feedback amplifier with feedback fraction β, the loop gain is defined as

In a Class A amplifier, the maximum theoretical efficiency is

In a Colpitts oscillator, the frequency of oscillation is determined by

The gain-bandwidth product (GBP) of an op-amp is approximately constant. For a 741 op-amp with GBP ≈ 1 MHz, the open-loop gain at 100 kHz is approximately

In a saturated BJT transistor used as a switch, the voltage drop VCE(sat) is typically

A BJT amplifier exhibits thermal runaway due to increased leakage current. Which design modification can best prevent this phenomenon?

Which configuration provides the highest input impedance and lowest output impedance among op-amp circuits?

For the oscillator to sustain oscillations, the loop gain must satisfy which condition (assuming phase shift is 360° or 0°)?

A Class B amplifier has two transistors operating in push-pull configuration. What is the maximum theoretical efficiency?

In an RC phase shift oscillator, how many RC sections are typically used to achieve 180° phase shift?

The Miller effect in a Common Emitter amplifier results in:

In a Wein bridge oscillator, the frequency of oscillation is given by f = 1/(2πRC). At what condition does oscillation start?

In a transimpedance amplifier (TIA), which parameter determines the transimpedance gain?

Which oscillator topology has the poorest frequency stability due to dependency on passive component tolerances?

For maximum power transfer from a source to load through an amplifier, what should be the relationship between source and load impedance?