Electronics (ECE) - MCQ Practice Questions

A combinational logic circuit implements a function where output Y = (A'BC) + (AB'C) + (ABC'). After minimization using K-map, the circuit requires minimum number of gates. Which of the following is the simplified expression?

The Miller effect in a common emitter amplifier causes

Negative feedback in an amplifier primarily results in

The Barkhausen criterion for oscillation states that

Which statement about thermal stability in BJT amplifiers is CORRECT?

In a Common Emitter amplifier, if the input impedance is 1 kΩ and the output impedance is 50 kΩ, what is the approximate voltage gain if β = 100 and gm = 0.04 S?

In a differential amplifier, Common Mode Rejection Ratio (CMRR) is measured as 80 dB. What is the numerical ratio of differential gain to common mode gain?

A feedback amplifier with closed-loop gain Acl = 10 has feedback fraction β = 0.1. What is the open-loop gain (A)?

In a two-stage amplifier with individual gains A₁ = 50 and A₂ = 100, if negative feedback β = 0.01 is applied across both stages, what is the approximate closed-loop gain?

In a Common Gate FET amplifier, how does the input impedance compare to Common Source?

A summing amplifier has three inputs with Rf = 100 kΩ. If R1 = R2 = R3 = 10 kΩ and inputs are V1 = 1V, V2 = 2V, V3 = 3V, what is the output?

In a feedback amplifier with loop gain L = Aβ, the closed-loop gain is approximately:

For a photodiode amplifier using trans-impedance configuration, increasing the feedback resistance Rf by 10 times will affect the noise figure and gain as:

A current mirror circuit using matched BJTs has output impedance of approximately:

In an instrumentation amplifier using three op-amps, what is the primary function of the first stage (two non-inverting amplifier configuration)?

A common-source FET amplifier with active load has voltage gain Av = -gm/gm,load. To maximize gain, which statement is true?

What is the maximum theoretical efficiency of a Class AB amplifier?

Which configuration minimizes the output impedance of an amplifier stage?

In a log amplifier circuit, what is the primary source of error in practical implementations?

For a bootstrapped voltage follower, what is the advantage over a standard buffer?