Amplifiers, Op-Amps, and Transistors Overview

The feedback resistor determines the stability of an op-amp circuit. (T/F)

True

The power efficiency of an amplifier is unaffected by the power supply voltage. (T/F)

False

Which quantity is used to express amplifier gain in decibels?

20log⁡(Vout/Vin)

Transconductance amplifiers produce an output voltage proportional to input current. (T/F)

False

Which of the following describes transresistance?

Vout/Iin

A lower output resistance in amplifiers leads to better power transfer to the load. (T/F)

True

What is the primary purpose of transfer characteristics in amplifiers?

Determine input/output relationship

Amplifiers with higher voltage gain always have better power efficiency. (T/F)

False

The significance of input resistance in amplifiers is that it determines loading effects.

Determine loading effects

Power amplifiers typically have the lowest input resistance among amplifier classes. (T/F)

True

Which amplifier type converts input voltage into output current?

Transconductance amplifier

An inverting op-amp configuration has a positive voltage gain. (T/F)

False

In a summing amplifier, the output voltage is proportional to:

The sum of all input voltages

Which op-amp circuit is designed to integrate an input signal?

Integrator

Input bias current in op-amps can lead to small output errors. (T/F)

True

Unity gain bandwidth is defined as:

The frequency where the open-loop gain equals 1

DC imperfections in op-amps only occur at high temperatures. (T/F)

False

What is the primary role of the feedback network in an op-amp?

Stabilize gain

Practical op-amps have infinite input impedance. (T/F)

False

What is the typical voltage gain of a non-inverting op-amp?

1+(Rf/Rin B)

Doping a semiconductor introduces free charge carriers. (T/F)

True

What current flow mechanism dominates in intrinsic semiconductors?

Diffusion Current

Forward bias in a pn junction widens the depletion region. (T/F)

False

IN a pn junction diode, reverse bias results in:

Widened depletion region

Intrinsic semiconductors have equal concentrations of holes and electrons. (T/F)

True

What is the primary function of a Zener diode?

Limit Voltage

A full-wave rectifier is more efficient than a half-wave rectifier. (T/F)

True

Which diode model best approzimates real behavior at voltages?

Constant voltage drop model

Diodes exhibit negative resistance in their forward bias region. (T/F)

False

How does load resistance affect a full-wave rectifier circuit?

Affects ripple voltage

MOSFETs operate with no gate current in DC analysis. (T/F)

True

What region of a MOSFET defined by VDS>(VGS−VT)?

Saturation

Transconductance measures how efficiently a MOSFET converts gate voltage to drain current. (T/F)

True

What is the primary parameter controlling BJT operation?

Base-emitter voltage

A BJT in saturation allows maximum current flow. (T/F)

True

What happens to a BJT in the cutoff region?

Both junctions are reverse-biased

The small-signal model for transistors is used for analyzing AC behavior. (T/F)

True

In the small-signal model, input resistance represents:

The resistance between base and emitter

MOSFETs require significant input power for operation. (T/F)

False

What parameter determines the threshold voltage of a MOSFET?

Gate oxide thickness