Define BJT amplifier.
A circuit that uses a bipolar junction transistor to amplify electrical signals.
What does BJT stand for?
Bipolar Junction Transistor.
True or false: BJTs are current-controlled devices.
TRUE
The output current is controlled by the input current in a BJT.
Fill in the blank: The three terminals of a BJT are the ______, base, and collector.
Emitter
What is the function of the base in a BJT?
It controls the flow of current between the emitter and collector.
Define common emitter configuration.
A BJT configuration where the emitter is common to both input and output circuits.
What is beta (β) in a BJT?
The current gain or amplification factor of the transistor.
True or false: The collector current is always greater than the base current.
TRUE
Fill in the blank: In a BJT, the input signal is applied to the ______ terminal.
Base
What is the role of the collector in a BJT amplifier?
It collects the charge carriers from the emitter and allows output current flow.
Define class A amplifier.
An amplifier that conducts for the entire input cycle, providing high linearity.
What is the main disadvantage of a class A amplifier?
It has low efficiency, typically around 20-30%.
True or false: Class B amplifiers conduct for half of the input signal cycle.
TRUE
Fill in the blank: The output of a BJT amplifier is taken from the ______ terminal.
Collector
What does input impedance refer to in a BJT amplifier?
The resistance seen by the input signal at the base terminal.
Define output impedance in the context of BJT amplifiers.
The resistance seen by the load connected to the collector terminal.
What is biasing in a BJT amplifier?
The process of setting a transistor’s operating point for optimal performance.
True or false: Negative feedback improves the stability of an amplifier.
TRUE
Fill in the blank: The DC biasing is essential for maintaining ______ in BJT amplifiers.
Linearity
What is the purpose of a coupling capacitor in amplifiers?
To block DC while allowing AC signals to pass between stages.
Define decoupling capacitor.
A capacitor used to filter out AC noise from the DC supply in amplifiers.
What is the frequency response of a BJT amplifier?
The range of frequencies over which the amplifier operates effectively.
True or false: Gain is the ratio of output signal to input signal in an amplifier.
TRUE
Fill in the blank: The voltage gain of a BJT amplifier is defined as ______.
Vout/Vin
