What is the main function of a Zener diode in a circuit?
A Signal modulation
B Voltage regulation
C Amplification
D Frequency conversion
A Zener diode is primarily used for voltage regulation. It allows current to flow in both directions but clamps the voltage to a set value when reverse biased, maintaining a stable output voltage for circuits.
What is the characteristic feature of a bipolar junction transistor (BJT)?
A Current-controlled device
B Low output impedance
C Voltage-controlled device
D High input impedance
A BJT is a current-controlled device, meaning that the current flowing into the base controls the current between the collector and emitter. This characteristic makes BJTs ideal for amplification purposes in analog circuits.
What is the primary purpose of a common-emitter amplifier configuration?
A Signal inversion
B Current regulation
C Voltage amplification
D Signal filtering
The common-emitter amplifier configuration is widely used for voltage amplification. It provides a high voltage gain and is often used in situations where signal amplification with phase inversion is needed.
What does “current gain” in a transistor refer to?
A Transistor’s power handling
B Voltage amplification
C Ratio of output to input voltage
D Ratio of output to input current
Current gain, denoted as β (beta), is the ratio of the collector current to the base current in a transistor. It indicates how effectively the transistor can amplify current in an amplifier circuit.
In a BJT, which terminal controls the flow of current between the collector and emitter?
A Base
B Gate
C Collector
D Emitter
In a Bipolar Junction Transistor (BJT), the base terminal controls the flow of current between the collector and emitter. A small current at the base can control a much larger current between the collector and emitter.
What is the purpose of a coupling capacitor in amplifier circuits?
A Voltage amplification
B Signal isolation
C Signal inversion
D Power supply regulation
A coupling capacitor is used in amplifier circuits to block DC components and allow only AC signals to pass through. This prevents the DC bias from affecting the next stage while transmitting the AC signal.
Which transistor type has high input impedance and is voltage-controlled?
A BJT
B NPN
C MOSFET
D PNP
The Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) has high input impedance and is voltage-controlled. Unlike BJTs, which are current-controlled, MOSFETs use voltage applied to the gate to control the flow of current between the drain and source.
What does the term “saturation” refer to in a transistor?
A Low input impedance
B High output current
C Maximum voltage output
D Maximum current through transistor
Saturation in a transistor refers to the state where the transistor is fully on and allowing the maximum current to flow from the collector to the emitter. This occurs when the base current is sufficiently high to saturate the transistor.
What is the role of a diode in a half-wave rectifier circuit?
A Filtering signal
B Amplifying signal
C Converting AC to DC
D Regulating voltage
In a half-wave rectifier, the diode allows current to flow in only one direction, converting alternating current (AC) to direct current (DC). It blocks the negative half of the AC signal, allowing only the positive half to pass through.
What type of amplifier configuration is most commonly used in audio applications?
A Common-emitter
B Common-collector
C Differential
D Common-base
The common-emitter configuration is widely used in audio applications due to its high voltage gain and its ability to amplify weak audio signals. It also provides phase inversion, which is generally acceptable in audio amplification.
What is the advantage of a transistor amplifier over a resistor-based amplifier?
A Higher efficiency
B Greater bandwidth
C More power consumption
D Higher stability
A transistor amplifier offers greater bandwidth compared to a resistor-based amplifier. It can amplify a wider range of frequencies effectively, which is essential for applications that require broad frequency response, like audio or RF amplifiers.
What is the typical use of a Schottky diode in circuits?
A Signal modulation
B Voltage regulation
C Low voltage rectification
D High current amplification
Schottky diodes are widely used for low voltage rectification due to their low forward voltage drop. They are ideal for high-speed switching applications, such as in power supplies and RF circuits, where efficiency is crucial.
Which amplifier configuration offers the highest current gain?
A Common-collector
B Differential
C Common-emitter
D Common-base
The common-collector amplifier configuration offers the highest current gain. It provides unity voltage gain but offers a high current gain, making it useful in impedance matching applications.
In a transistor, what does the term “active region” refer to?
A Saturated region
B Low current region
C Region where transistor is off
D Region where transistor amplifies
The active region of a transistor is where it functions as an amplifier. In this region, the transistor is biased in such a way that it can amplify the input signal, making it suitable for use in analog circuits.
Which of the following is a common application of a transistor in analog circuits?
A Signal amplification
B Signal conversion
C Digital logic processing
D Noise filtering
Transistors are most commonly used in analog circuits for signal amplification. They take weak electrical signals and amplify them, making them stronger for use in various applications like audio systems, radios, and communication equipment.