What is the primary function of a Field-Effect Transistor (FET)?
A Signal amplification
B Current control
C Signal modulation
D Voltage regulation
A Field-Effect Transistor (FET) is mainly used for signal amplification in analog circuits. It amplifies weak electrical signals, and its voltage-controlled nature allows it to be used in a variety of applications, including RF and audio amplification.
What is the typical characteristic of an operational amplifier (op-amp)?
A High current gain
B Low output impedance
C High input impedance
D Low voltage gain
An operational amplifier (op-amp) is designed to have a very high input impedance and low output impedance. This allows it to amplify weak signals with minimal loss, making it ideal for a variety of analog signal processing tasks.
In a common-source FET amplifier, which terminal acts as the input?
A Drain
B Source
C Emitter
D Gate
In a common-source FET amplifier, the gate is the input terminal. The voltage applied to the gate controls the current flow between the source and drain, and it is used to modulate the amplification of the input signal.
What is the main advantage of using op-amps in feedback circuits?
A Low power consumption
B Stable gain
C High output voltage
D High frequency response
The main advantage of using op-amps in feedback circuits is the stabilization of gain. Negative feedback is commonly employed to reduce distortion, increase bandwidth, and maintain a consistent gain over a wide range of frequencies.
What does a differential amplifier amplify?
A Power
B Current difference
C Voltage difference
D Voltage level
A differential amplifier amplifies the difference in voltage between two input signals. It rejects common-mode signals (those that are identical on both inputs) and is widely used in applications like sensor signal conditioning and audio processing.
Which configuration of FET is most commonly used for amplifying signals?
A Common-source
B Common-base
C Common-drain
D Common-gate
The common-source configuration of a FET is most commonly used for signal amplification due to its high gain and versatility. It provides a significant voltage gain and is widely used in amplifiers for both small and large signals.
What is the purpose of a feedback resistor in an op-amp circuit?
A Decrease noise
B Stabilize signal
C Limit power
D Increase gain
A feedback resistor in an op-amp circuit is used to control the gain of the amplifier. It allows a portion of the output signal to be fed back into the input, effectively increasing the amplifier’s gain and ensuring it operates within the desired range.
In an op-amp, what happens when the differential input voltage is zero?
A Output is infinite
B Output is non-zero
C Output is zero
D Output is constant
In an ideal op-amp, when the differential input voltage is zero (i.e., both inputs are at the same potential), the output is zero. This is because there is no difference between the inputs to amplify.
What is the primary use of a voltage follower circuit using an op-amp?
A Frequency modulation
B Voltage buffering
C Signal inversion
D Signal amplification
A voltage follower circuit, using an op-amp, is primarily used for voltage buffering. It provides unity gain, meaning the output follows the input voltage, but the high input impedance and low output impedance prevent signal loss and loading effects.
What does the term “slew rate” refer to in an op-amp?
A Rate of voltage change
B Rate of current change
C Rate of gain change
D Rate of output signal stability
Slew rate refers to the maximum rate at which an op-amp’s output voltage can change in response to a rapid change in the input voltage. A higher slew rate is beneficial in applications where fast signal transitions are necessary, such as in high-speed amplifiers.
What is a common use of a MOSFET in analog circuits?
A Digital switching
B Oscillation
C Amplification
D Rectification
MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) are commonly used for signal amplification in analog circuits. They provide high input impedance and are widely used in both small-signal and power amplifiers, especially in high-frequency applications.
What is the effect of increasing the feedback resistance in an op-amp circuit?
A Increase bandwidth
B Decrease bandwidth
C Decrease gain
D Increase gain
Increasing the feedback resistance in an op-amp circuit increases the gain of the amplifier. Feedback resistance controls the amount of the output signal fed back into the input, which directly impacts the overall gain of the circuit.
What happens when the gate-to-source voltage in a FET exceeds the threshold voltage?
A Source current decreases
B Drain current increases
C Gate current increases
D Drain current stops
When the gate-to-source voltage in a FET exceeds the threshold voltage, it creates an inversion layer between the drain and source, allowing current to flow. As the voltage increases further, the drain current also increases, enhancing the amplification.
Which type of amplifier is most commonly used for voltage amplification?
A Differential
B Common-collector
C Common-source
D Common-emitter
The common-source configuration of a FET amplifier is most commonly used for voltage amplification. It provides a high voltage gain and is widely used in audio and RF amplification circuits due to its simplicity and performance.
What is the function of the non-inverting terminal in an op-amp circuit?
A Amplify signal
B Set gain
C Maintain stability
D Provide bias
The non-inverting terminal in an op-amp circuit is used to input the signal that will be amplified. The output of the op-amp follows the input signal, providing a gain without inversion, making it suitable for various applications like buffering and amplifying.