What are majority carriers in an n type semiconductor?
A Holes
B Electrons
C Protons
D Neutrons
In an n type semiconductor, electrons are the majority carriers. They are provided by donor impurities (like phosphorus) and contribute to electrical conduction, making n type semiconductors efficient for current flow.
What is the purpose of a MOSFET in electronic circuits?
A Switching
B Signal amplification
C Voltage control
D Current rectification
A Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is primarily used as a switch in digital circuits. It controls the flow of current between the source and drain based on the voltage applied to the gate terminal.
In a p channel MOSFET, where does the current flow?
A Source to drain
B Base to emitter
C Drain to source
D Collector to emitter
In a p channel MOSFET, current flows from the drain to the source when a negative voltage is applied to the gate. The charge carriers in p channel MOSFETs are holes, which are the majority carriers.
What is CMOS technology used for?
A Signal amplification
B Current rectification
C Light emission
D Digital logic circuits
Complementary Metal Oxide Semiconductor (CMOS) technology is widely used in digital logic circuits, microprocessors, and memory devices. It uses both p channel and n channel MOSFETs to create low power, high performance circuits.
What happens when a p type semiconductor is connected to an n type semiconductor?
A Formation of depletion region
B Formation of magnetic field
C Increased resistance
D Current flow in both directions
When a p type semiconductor is connected to an n type semiconductor, a p n junction is formed. This junction creates a depletion region where electrons from the n type region recombine with holes from the p type region, preventing current flow under reverse bias.
In a MOSFET, what is the role of the gate?
A Collect charge carriers
B Control current flow
C Emit charge carriers
D Amplify signals
The gate of a MOSFET controls the flow of current between the source and drain by applying a voltage. This voltage modulates the conductivity of the semiconductor channel, allowing the MOSFET to act as a switch or amplifier.
What happens when a MOSFET is in the “cutoff” region?
A Transistor is off
B Transistor conducts current
C Transistor amplifies signal
D Transistor has high resistance
When a MOSFET is in the cutoff region, it behaves like an open switch, meaning no current flows between the drain and source. The MOSFET is essentially “off” as the gate source voltage is below the threshold.
What is the primary function of a bipolar junction transistor (BJT)?
A Voltage regulation
B Current rectification
C Signal amplification
D Light detection
A BJT is primarily used for amplifying electrical signals. A small input current at the base controls a larger current flowing between the collector and emitter, enabling signal amplification in various electronic applications.
Which material is commonly used to manufacture MOSFETs?
A Silicon
B Gallium Arsenide
C Germanium
D Copper
Silicon is the most commonly used material for manufacturing MOSFETs due to its excellent semiconductor properties, availability, and cost effectiveness. Silicon based MOSFETs are widely used in modern electronics for switching and amplification.
What is the significance of the threshold voltage in a MOSFET?
A Determines current
B Determines switching speed
C Determines power dissipation
D Determines gate voltage required for conduction
The threshold voltage of a MOSFET is the minimum gate source voltage required to create a conductive channel between the source and drain. Below this voltage, the MOSFET does not conduct current.
What is the primary characteristic of a p type semiconductor?
A Excess electrons
B Excess holes
C Low conductivity
D High resistivity
A p type semiconductor has an abundance of holes, which are created by the presence of acceptor impurities. These holes act as positive charge carriers and allow electrical conduction in the material.
How does the size of the MOSFET affect its switching speed?
A Larger size increases switching speed
B Size has no effect on switching speed
C Smaller size increases switching speed
D Smaller size decreases switching speed
A smaller MOSFET size allows for faster switching speeds because it reduces the capacitance and increases the response time of the device. This is essential for high speed digital circuits and microprocessors.
What is the primary difference between N channel and P channel MOSFETs?
A Threshold voltage
B Channel material
C Gate voltage polarity
D Current direction
The primary difference between N channel and P channel MOSFETs is the direction of current flow. In an N channel MOSFET, electrons are the majority carriers, and current flows from the drain to the source. In a P channel MOSFET, holes are the majority carriers, and current flows from the source to the drain.
What is the role of the source in a MOSFET?
A Emit charge carriers
B Collect charge carriers
C Supply charge carriers
D Apply voltage
The source in a MOSFET provides charge carriers (electrons or holes) to the channel. When the gate voltage is sufficient to form a conductive channel, the charge carriers from the source flow to the drain.
In a CMOS circuit, why are both p channel and n channel MOSFETs used together?
A To reduce power consumption
B To increase voltage
C To increase current flow
D To amplify signals
CMOS technology uses both p channel and n channel MOSFETs to reduce power consumption. The complementary nature of the two types of MOSFETs ensures that current flows only during switching, minimizing energy loss and improving efficiency in digital circuits.