Q. In a p-n junction, what happens when the junction is forward biased? (2019)
A.
Depletion region widens
B.
Depletion region narrows
C.
No current flows
D.
Reverse current increases
Show solution
Solution
When a p-n junction is forward biased, the depletion region narrows, allowing current to flow.
Correct Answer:
B
— Depletion region narrows
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Q. In a p-n junction, which type of charge carriers are majority carriers in the p-type region? (2019)
A.
Electrons
B.
Holes
C.
Protons
D.
Neutrons
Show solution
Solution
In the p-type region of a p-n junction, holes are the majority charge carriers.
Correct Answer:
B
— Holes
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Q. In a p-n junction, which type of charge carriers are predominant in the p-type region? (2019)
A.
Electrons
B.
Holes
C.
Protons
D.
Neutrons
Show solution
Solution
In a p-type region, holes are the predominant charge carriers.
Correct Answer:
B
— Holes
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Q. In a PN junction diode, the depletion region is formed due to: (2019)
A.
Excess electrons
B.
Excess holes
C.
Recombination of electrons and holes
D.
External voltage
Show solution
Solution
The depletion region in a PN junction diode is formed due to the recombination of electrons and holes at the junction.
Correct Answer:
C
— Recombination of electrons and holes
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Q. In a PN junction diode, what happens when it is forward biased? (2019)
A.
Depletion region widens
B.
Depletion region narrows
C.
No current flows
D.
Reverse current increases
Show solution
Solution
When a PN junction diode is forward biased, the depletion region narrows, allowing current to flow.
Correct Answer:
B
— Depletion region narrows
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Q. In a PN junction, what is formed at the junction of p-type and n-type materials? (2021)
A.
Electric field
B.
Magnetic field
C.
Thermal field
D.
Gravitational field
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Solution
An electric field is formed at the junction of p-type and n-type materials due to the diffusion of charge carriers.
Correct Answer:
A
— Electric field
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Q. In a PN junction, what is the region called where no charge carriers are present? (2019)
A.
Depletion region
B.
Conduction band
C.
Valence band
D.
Neutral zone
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Solution
The depletion region is the area around the PN junction where no free charge carriers are present.
Correct Answer:
A
— Depletion region
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Q. In a semiconductor, what happens to the conductivity as temperature increases? (2021)
A.
Decreases
B.
Increases
C.
Remains constant
D.
Becomes zero
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Solution
The conductivity of a semiconductor increases with temperature due to more charge carriers being available.
Correct Answer:
B
— Increases
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Q. In a Zener diode, what is the purpose of the reverse breakdown region? (2020)
A.
To increase voltage
B.
To regulate voltage
C.
To decrease current
D.
To store energy
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Solution
The reverse breakdown region in a Zener diode allows it to regulate voltage by maintaining a constant output voltage.
Correct Answer:
B
— To regulate voltage
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Q. The forward bias condition in a diode occurs when: (2020)
A.
Anode is at a higher potential than cathode
B.
Cathode is at a higher potential than anode
C.
Both terminals are at the same potential
D.
None of the above
Show solution
Solution
In forward bias, the anode is connected to a higher potential than the cathode, allowing current to flow.
Correct Answer:
A
— Anode is at a higher potential than cathode
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Q. What happens to the resistance of a semiconductor as it is illuminated? (2022)
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes infinite
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Solution
The resistance of a semiconductor decreases when it is illuminated due to the generation of electron-hole pairs.
Correct Answer:
B
— Decreases
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Q. What happens to the resistance of a semiconductor as temperature increases? (2021)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes infinite
Show solution
Solution
The resistance of a semiconductor decreases with an increase in temperature due to the increased number of charge carriers.
Correct Answer:
B
— Decreases
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Q. What happens to the resistance of a semiconductor with an increase in temperature? (2023)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes infinite
Show solution
Solution
The resistance of a semiconductor decreases with an increase in temperature due to the increased number of charge carriers.
Correct Answer:
B
— Decreases
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Q. What is the effect of temperature on the conductivity of intrinsic semiconductors? (2021)
A.
Conductivity decreases
B.
Conductivity remains constant
C.
Conductivity increases
D.
Conductivity becomes zero
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Solution
As temperature increases, more electrons gain enough energy to jump the band gap, increasing conductivity.
Correct Answer:
C
— Conductivity increases
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Q. What is the effect of temperature on the conductivity of semiconductors? (2019)
A.
Conductivity decreases
B.
Conductivity remains constant
C.
Conductivity increases
D.
Conductivity becomes zero
Show solution
Solution
As temperature increases, the conductivity of semiconductors increases due to the generation of more charge carriers.
Correct Answer:
C
— Conductivity increases
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Q. What is the energy band gap of a typical semiconductor? (2021)
A.
0.1 eV
B.
1.1 eV
C.
2.0 eV
D.
3.5 eV
Show solution
Solution
The energy band gap of a typical semiconductor like silicon is approximately 1.1 eV.
Correct Answer:
B
— 1.1 eV
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Q. What is the function of a diode in a circuit? (2020)
A.
To store energy
B.
To amplify signals
C.
To allow current to flow in one direction
D.
To resist current flow
Show solution
Solution
A diode allows current to flow in one direction only, acting as a one-way valve for electric current.
Correct Answer:
C
— To allow current to flow in one direction
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Q. What is the function of a transistor in a circuit? (2021)
A.
Amplification
B.
Rectification
C.
Capacitance
D.
Inductance
Show solution
Solution
A transistor is primarily used for amplification of signals in electronic circuits.
Correct Answer:
A
— Amplification
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Q. What is the main function of a transistor? (2022)
A.
Rectification
B.
Amplification
C.
Capacitance
D.
Inductance
Show solution
Solution
The main function of a transistor is to amplify electrical signals.
Correct Answer:
B
— Amplification
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Q. What is the primary function of a diode? (2022)
A.
To amplify current
B.
To rectify current
C.
To store charge
D.
To generate voltage
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Solution
A diode primarily functions to rectify current, allowing it to flow in one direction only.
Correct Answer:
B
— To rectify current
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Q. What is the principle behind a photodiode? (2022)
A.
Thermal emission
B.
Photoelectric effect
C.
P-N junction
D.
Capacitance
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Solution
A photodiode operates on the principle of the photoelectric effect, where light generates electron-hole pairs.
Correct Answer:
B
— Photoelectric effect
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Q. What is the role of a capacitor in a semiconductor circuit? (2019)
A.
To store charge
B.
To amplify signals
C.
To rectify current
D.
To generate heat
Show solution
Solution
A capacitor is used in semiconductor circuits to store charge temporarily.
Correct Answer:
A
— To store charge
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Q. What is the role of a diode in a rectifier circuit? (2022)
A.
To amplify signals
B.
To store charge
C.
To allow current in one direction
D.
To increase voltage
Show solution
Solution
In a rectifier circuit, a diode allows current to flow in one direction, converting AC to DC.
Correct Answer:
C
— To allow current in one direction
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Q. What is the role of a doping element in a semiconductor? (2020)
A.
To increase resistance
B.
To decrease temperature
C.
To change the conductivity
D.
To create a magnetic field
Show solution
Solution
Doping elements are added to semiconductors to change their conductivity by introducing additional charge carriers.
Correct Answer:
C
— To change the conductivity
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Q. What is the role of a resistor in a semiconductor circuit? (2023)
A.
Increase current
B.
Limit current
C.
Store charge
D.
Amplify signal
Show solution
Solution
A resistor is used to limit the current flowing through a semiconductor circuit to prevent damage.
Correct Answer:
B
— Limit current
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Q. What is the role of doping in semiconductors? (2022)
A.
To increase resistance
B.
To decrease conductivity
C.
To introduce charge carriers
D.
To create a magnetic field
Show solution
Solution
Doping introduces additional charge carriers (electrons or holes) into the semiconductor, enhancing its conductivity.
Correct Answer:
C
— To introduce charge carriers
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Q. What is the typical current-voltage characteristic of a diode in reverse bias? (2019)
A.
Linear
B.
Exponential
C.
Constant
D.
Very small reverse saturation current
Show solution
Solution
In reverse bias, a diode exhibits a very small reverse saturation current until breakdown occurs.
Correct Answer:
D
— Very small reverse saturation current
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Q. What is the typical forward voltage drop across a silicon diode? (2023)
A.
0.2 V
B.
0.7 V
C.
1.5 V
D.
2.0 V
Show solution
Solution
The typical forward voltage drop across a silicon diode is approximately 0.7 V.
Correct Answer:
B
— 0.7 V
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Q. What type of charge carriers are predominant in n-type semiconductors? (2020)
A.
Holes
B.
Electrons
C.
Protons
D.
Neutrons
Show solution
Solution
In n-type semiconductors, electrons are the predominant charge carriers.
Correct Answer:
B
— Electrons
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Q. What type of charge carriers are present in n-type semiconductors? (2019)
A.
Holes
B.
Electrons
C.
Protons
D.
Neutrons
Show solution
Solution
In n-type semiconductors, the majority charge carriers are electrons.
Correct Answer:
B
— Electrons
Learn More →
Showing 1 to 30 of 47 (2 Pages)
Modern Physics - Semiconductor Electronics MCQ & Objective Questions
Modern Physics, particularly the study of Semiconductor Electronics, plays a crucial role in various school and competitive exams. Understanding this topic not only enhances your conceptual clarity but also boosts your confidence in tackling objective questions. Practicing MCQs and important questions related to Semiconductor Electronics is essential for effective exam preparation, helping you score better and grasp key concepts.
What You Will Practise Here
Fundamentals of semiconductors: intrinsic and extrinsic types
Energy bands and band gap theory
PN junctions and their characteristics
Diodes: types, applications, and working principles
Transistors: Bipolar Junction Transistors (BJTs) and Field Effect Transistors (FETs)
Applications of semiconductor devices in modern technology
Key formulas and definitions related to semiconductor physics
Exam Relevance
The topic of Semiconductor Electronics is frequently featured in CBSE, State Boards, NEET, and JEE exams. Students can expect questions that assess their understanding of semiconductor properties, device operations, and applications. Common question patterns include multiple-choice questions that require a solid grasp of concepts and the ability to apply them in practical scenarios.
Common Mistakes Students Make
Confusing intrinsic and extrinsic semiconductors and their properties
Misunderstanding the operation of PN junctions and their IV characteristics
Overlooking the significance of temperature effects on semiconductor behavior
Failing to apply the correct formulas in problem-solving scenarios
FAQs
Question: What are the key differences between BJTs and FETs?Answer: BJTs are current-controlled devices, while FETs are voltage-controlled. This fundamental difference affects their applications and performance in circuits.
Question: How do temperature changes affect semiconductor performance?Answer: Temperature variations can significantly influence carrier concentration and mobility, impacting the conductivity and overall performance of semiconductor devices.
Now is the time to enhance your understanding and confidence in Modern Physics - Semiconductor Electronics. Dive into our practice MCQs and test your knowledge to excel in your exams!
