What type of charge carriers dominate in a p type semiconductor?
A Holes
B Electrons
C Protons
D Neutrons
In a p type semiconductor, the majority carriers are holes. These holes are created by the absence of electrons in the valence band and move through the material, facilitating electrical conduction by acting as positive charge carriers.
What is the main function of the depletion region in a p n junction diode?
A Allow current flow
B Amplify signals
C Control voltage
D Block current flow
The depletion region in a p n junction diode is formed when electrons from the n type material combine with holes from the p type material. This region prevents current flow under reverse bias, enabling the diode’s rectifying properties.
What is the primary material used in the fabrication of most integrated circuits (ICs)?
A Gallium Arsenide
B Silicon
C Copper
D Germanium
Silicon is the most widely used material for fabricating integrated circuits (ICs). Its semiconductor properties, abundance, and cost effectiveness make it ideal for manufacturing microchips, transistors, and other semiconductor devices.
In a diode, what is the characteristic of the reverse biased region?
A High current
B High voltage
C Low current
D No current
In the reverse biased region, the p type side is connected to the negative terminal, and the n type side to the positive terminal. This results in a wide depletion region and blocks current flow, with only a very small leakage current in most cases.
What does the band gap of a semiconductor determine?
A Conductivity
B Carrier mobility
C Current flow
D Voltage drop
The band gap of a semiconductor determines its conductivity. A small band gap allows for easier electron excitation from the valence band to the conduction band, leading to higher conductivity, while a large band gap limits this process.
What happens to the conductivity of a semiconductor as temperature increases?
A Increases
B Decreases
C Remains constant
D Becomes zero
As the temperature increases, more electrons gain enough thermal energy to jump from the valence band to the conduction band, increasing the number of free charge carriers and thereby increasing the conductivity of the semiconductor.
What is the primary function of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor)?
A Current switching
B Signal amplification
C Light emission
D Current regulation
A MOSFET is primarily used for switching electronic signals. It controls the current flow between the source and drain terminals by applying a voltage to the gate, allowing it to function in digital circuits, memory, and amplifiers.
What is the role of doping in semiconductors?
A Increase resistance
B Decrease current
C Control carrier concentration
D Increase voltage
Doping involves adding impurities to a semiconductor to increase or decrease the concentration of charge carriers (electrons or holes). This process is essential in creating p type or n type semiconductors with desired electrical properties.
What is the main advantage of using CMOS technology in digital circuits?
A High power consumption
B Low power consumption
C High speed
D High signal gain
CMOS (Complementary Metal Oxide Semiconductor) technology uses both p type and n type MOSFETs. It is known for its low power consumption, making it ideal for use in microprocessors, memory devices, and digital circuits that require minimal energy usage.
What happens when a transistor is biased in the cutoff region?
A It behaves like an open switch
B It amplifies signals
C It conducts maximum current
D It generates noise
When a transistor is biased in the cutoff region, the base emitter junction is not forward biased, and no current flows between the collector and emitter. The transistor behaves like an open switch, preventing current flow.
What is the effect of increasing the base emitter voltage in a BJT (Bipolar Junction Transistor)?
A Decrease current
B No change in current
C Increase current
D Turn the transistor off
Increasing the base emitter voltage in a BJT forward biases the base emitter junction, allowing more current to flow from the emitter to the collector. This increases the collector current, enabling the transistor to amplify signals.
What type of current does a solar cell generate?
A Alternating current
B Pulsating current
C High frequency current
D Direct current
A solar cell generates direct current (DC) when it converts light energy into electrical energy. Photons from light excite electrons in the semiconductor material, generating a unidirectional current, which is typically used for charging batteries and powering devices.
What is the primary function of a Hall effect sensor?
A Measure current
B Measure magnetic field
C Measure voltage
D Measure temperature
A Hall effect sensor detects the presence and strength of a magnetic field. When a magnetic field is applied perpendicular to the flow of current in a conductor, a voltage (Hall voltage) is generated, which can be measured to determine the magnetic field strength.
What is the primary feature of a direct bandgap semiconductor?
A Low conductivity
B High energy band gap
C Efficient light emission
D High resistivity
Direct bandgap semiconductors, such as Gallium Arsenide, can efficiently emit light when electrons transition from the conduction band to the valence band. This property makes them ideal for use in LEDs, lasers, and optical communication devices.
What is the primary application of a phototransistor?
A Light detection
B Signal modulation
C Signal amplification
D Voltage regulation
A phototransistor detects light and converts it into an electrical signal. It works similarly to a regular transistor but is more sensitive to light, making it ideal for applications such as optical sensors and communication systems.