What is the primary purpose of a differential amplifier?
A Amplify DC signals
B Amplify the difference between two input signals
C Block noise signals
D Amplify both input signals equally
A differential amplifier amplifies the voltage difference between two input signals, making it effective for rejecting common-mode noise and interference.
What type of signal is analyzed in small-signal analysis?
A High-frequency signal
B Low-frequency signal
C Large amplitude signal
D Small amplitude signal
Small-signal analysis focuses on linearizing and analyzing the behavior of a circuit for small amplitude signals around a bias point.
Which parameter of an amplifier represents the maximum frequency it can handle effectively?
A Bandwidth
B Slew rate
C Frequency response
D Gain
Bandwidth is the range of frequencies over which an amplifier can operate effectively with minimal signal attenuation.
What is the role of a gain-bandwidth product (GBP) in an amplifier?
A To define noise immunity
B To measure stability
C To define the trade-off between gain and bandwidth
D To increase power efficiency
The gain-bandwidth product is constant for an amplifier, meaning that increasing gain reduces bandwidth, and vice versa.
Which class of power amplifiers operates for the entire 360° of the input cycle?
A Class A
B Class B
C Class AB
D Class C
Class A amplifiers conduct for the full 360° of the input signal cycle, ensuring high fidelity but lower efficiency compared to other classes.
What is the purpose of a waveform generator?
A To filter signals
B To produce specific waveforms like sine, square, and triangle waves
C To rectify AC signals
D To amplify low signals
Waveform generators are used in testing and designing circuits by providing various periodic signals with adjustable parameters.
What is the most common cause of harmonic distortion in amplifiers?
A Operating in the linear region
B Nonlinear behavior of components
C Low-frequency signals
D Thermal noise
Harmonic distortion arises when amplifiers operate in nonlinear regions, producing harmonics of the input signal.
What is the function of a filter in a signal conditioning circuit?
A Amplify signals
B Block specific frequencies while allowing others
C Convert AC to DC
D Generate waveforms
Filters selectively allow or block specific frequency ranges to shape the signal as required, such as removing noise or isolating a desired frequency band.
What type of distortion is caused by the overlapping of two frequencies in a circuit?
A Harmonic distortion
B Crossover distortion
C Intermodulation distortion
D Frequency distortion
Intermodulation distortion occurs when two or more frequencies mix in a nonlinear system, producing unwanted signals at other frequencies.
What is the effect of increasing capacitance in a low-pass RC filter?
A Increases the cut-off frequency
B Decreases the cut-off frequency
C Has no effect on the cut-off frequency
D Increases gain
In an RC low-pass filter, the cut-off frequency is inversely proportional to capacitance. Increasing capacitance lowers the cut-off frequency, allowing only lower frequencies to pass.
What is the purpose of a differentiator circuit?
A To produce the integral of the input signal
B To produce the derivative of the input signal
C To generate waveforms
D To amplify noise signals
Differentiator circuits output a voltage proportional to the rate of change (derivative) of the input signal, making them useful in edge detection applications.
Which parameter measures the ability of an amplifier to reject noise on both input lines?
A Slew rate
B Common-mode rejection ratio (CMRR)
C Gain-bandwidth product
D Input impedance
CMRR quantifies an amplifier’s ability to reject common-mode signals (noise) and amplify only the difference between input signals.
Which component is essential in designing integrators and differentiators?
A Inductor
B Resistor
C Capacitor
D Diode
Capacitors are key components in integrators and differentiators as their reactance depends on the frequency, enabling the desired signal processing.
Which type of power amplifier is most suitable for audio applications?
A Class A
B Class B
C Class AB
D Class D
Class AB amplifiers combine the high fidelity of Class A with the efficiency of Class B, making them ideal for audio applications.
What is a primary drawback of a high-frequency signal in small-signal analysis?
A Increased bandwidth
B Stray capacitance and inductance effects
C Higher gain
D Reduced noise
At high frequencies, parasitic capacitances and inductances dominate, distorting the signal and limiting the circuit’s performance.