Physics
Semiconductors and Diodes
461 Questions
Semiconductors and diodes form the foundation of modern electronics, covering topics like intrinsic carrier concentration and Zener breakdown. Questions often explore the characteristics of bipolar junction transistors (BJT) and the properties of doped silicon materials. This topic is crucial for physics and electronics engineering competitive exams.
Zener diode breakdownBJT circuit analysisIntrinsic carrier concentrationDoping in semiconductorsEmitter follower circuit
Semiconductors and Diodes Questions
What is the minority carrier in a p-type semiconductor?
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Electrons
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Holes
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Neutrons
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Protons
B
Correct answer
Explanation
The minority carrier in a p-type semiconductor is holes.
What is the process of creating a p-n junction?
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Diffusion
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Epitaxy
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Ion implantation
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Oxidation
A
Correct answer
Explanation
The process of creating a p-n junction is diffusion, where impurities are introduced into a semiconductor to create regions of different conductivity types.
What is the function of a p-n junction diode?
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To allow current to flow in one direction only
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To amplify signals
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To generate light
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To store charge
A
Correct answer
Explanation
The function of a p-n junction diode is to allow current to flow in one direction only.
What is the name of the region in a semiconductor where the majority and minority carriers recombine?
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Depletion region
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Space charge region
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Recombination region
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Active region
C
Correct answer
Explanation
The name of the region in a semiconductor where the majority and minority carriers recombine is the recombination region.
What is the name of the phenomenon where the current in a semiconductor increases with increasing temperature?
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Thermal runaway
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Avalanche breakdown
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Zener breakdown
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Intrinsic breakdown
A
Correct answer
Explanation
The name of the phenomenon where the current in a semiconductor increases with increasing temperature is thermal runaway.
What is the name of the device that uses the photoconductivity effect to detect light?
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Photodiode
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Phototransistor
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Light-emitting diode
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Solar cell
A
Correct answer
Explanation
The name of the device that uses the photoconductivity effect to detect light is a photodiode.
What is the primary limitation of electrostatic solid state actuators in high-power applications?
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Low force output
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High power consumption
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Limited displacement range
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All of the above
D
Correct answer
Explanation
Electrostatic solid state actuators have limitations such as low force output, high power consumption, and limited displacement range in high-power applications.
What is the primary material used in the manufacture of transistors?
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Silicon
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Germanium
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Gallium Arsenide
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Indium Phosphide
A
Correct answer
Explanation
Silicon is the primary material used in the manufacture of transistors due to its excellent electrical properties and its ability to be easily processed.
What is the effect of strain on the bandgap of a Quantum Well?
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Strain increases the bandgap.
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Strain decreases the bandgap.
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Strain has no effect on the bandgap.
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Strain changes the sign of the bandgap.
B
Correct answer
Explanation
Strain decreases the bandgap of a Quantum Well. This is because strain changes the crystal structure of the semiconductor material, which in turn changes the energy levels of the electrons and holes.
What is the effect of doping on the bandgap of a Quantum Well?
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Doping increases the bandgap.
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Doping decreases the bandgap.
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Doping has no effect on the bandgap.
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Doping changes the sign of the bandgap.
B
Correct answer
Explanation
Doping decreases the bandgap of a Quantum Well. This is because doping introduces impurities into the semiconductor material, which change the energy levels of the electrons and holes.
What is the main limitation of Plasma Display Panels (PDPs) compared to other Solid State Display technologies?
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Higher power consumption
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Shorter lifespan
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Lower image quality
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All of the above
D
Correct answer
Explanation
PDPs have higher power consumption, shorter lifespan, and lower image quality compared to other Solid State Display technologies.
How do CMOS sensors work?
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By converting light into electrical signals
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By converting electrical signals into light
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By amplifying light signals
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By filtering light signals
A
Correct answer
Explanation
CMOS sensors work by converting light into electrical signals through a process called photoelectric effect.
What is the quantum efficiency of a CMOS sensor?
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The percentage of photons that are converted into electrical signals by the sensor
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The percentage of photons that are reflected by the sensor
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The percentage of photons that are absorbed by the sensor
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The percentage of photons that are transmitted through the sensor
A
Correct answer
Explanation
Quantum efficiency is the percentage of photons that are converted into electrical signals by the CMOS sensor.
What is the resolution of a CMOS sensor?
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The number of pixels on the sensor
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The pixel size of the sensor
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The dynamic range of the sensor
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The quantum efficiency of the sensor
A
Correct answer
Explanation
Resolution is the number of pixels on the CMOS sensor, typically expressed in megapixels (MP).
What is the energy bandgap in a semiconductor?
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The difference between the valence band and the conduction band
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The difference between the Fermi level and the conduction band
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The difference between the valence band and the Fermi level
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The difference between the conduction band and the Fermi level
A
Correct answer
Explanation
The energy bandgap in a semiconductor is the difference between the valence band and the conduction band. It determines the electrical properties of the semiconductor.