Semiconductor Devices & Circuits Flashcards
7 cards from real CET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Semiconductor Devices & Circuits flashcards as text
What is the primary function of a Zener diode in a circuit?
Answer: Regulate voltage by operating in reverse breakdown
A Zener diode is specifically designed to maintain a stable reference voltage when reverse biased at its breakdown voltage.
In an NPN transistor, which terminal is the source of electrons during normal active-region operation?
Answer: Emitter
In an NPN transistor, the emitter injects (emits) electrons into the base region during forward-active operation.
A silicon diode has a forward voltage drop of approximately:
Answer: 0.7 V
Silicon diodes have a characteristic forward voltage drop (barrier potential) of approximately 0.6–0.7 V.
What does the parameter hFE (or β) represent for a BJT transistor?
Answer: DC current gain (IC/IB)
hFE (β) is the DC current gain, defined as the ratio of collector current to base current in a BJT.
Which biasing configuration for a BJT provides the most stable Q-point against temperature variations?
Answer: Voltage-divider bias
Voltage-divider bias sets the base voltage independently of β, making the Q-point very stable over temperature and device variation.
In a MOSFET, the channel conductivity is controlled by the voltage applied to which terminal?
Answer: Gate
The gate voltage creates or modulates the inversion channel between source and drain, controlling drain current.
A full-wave bridge rectifier uses how many diodes?
Answer: 4
A full-wave bridge rectifier uses four diodes arranged so both half-cycles of the AC input produce positive output.