Semiconductor Electronics: Materials, Devices and Simple Circuits

CBSE Class 12 Physics · every board question from this chapter, 2022–2026 · 72 of them repeated across years

• If the given figure, V 0 is the potential barrier across a p-n junction in an unbiased condition. Which of the following…2026
• Which of the following p-n junction diodes is forward biased?2026
• When the forward bias voltage in a semiconductor diode is changed from 0.8 V to 1.0 V, the forward current changes by 2.0 mA. The…2026asked 3×
• A good diode checked by a multimeter should indicate:2026asked 3×
• In an unbiased p-n junction, at equilibrium, which of the following statements is true?2026asked 3×
• In a reversed-biased p-n junction diode, the applied voltage mostly drops across:2026asked 3×
• The process named 'minority carrier injection' in a p-n junction diode occurs during:2026
• Assertion: On forward biasing a p-n junction diode, the height of the barrier potential increases. Reason (R): In forward biasing…2026asked 3×
• Assertion: The conductivity of an n -type semiconductor is higher than that of a p-type semiconductor at a given temperature.…2026asked 3×
• Write two points of difference between intrinsic and extrinsic semiconductors.2026asked 4×
• Explain, with the help of suitable diagram, the two important processes that occur during the formation of a p-n junction.2026
• How are charge carriers created in an intrinsic semiconductor? Explain.2026
• The hole concentration in an intrinsic semiconductor is 5 × 10^8 m^-3. When it is doped with certain impurity, the electron…2026asked 3×
• Suppose a pure Si crystal has 5 × 10^28 atoms per m^3. It is doped with 5 × 10^22 atoms per m^3 of Arsenic. Calculate the…2026asked 3×
• An ac voltage V i=12 sin (100 π t) V is applied between points A and B in a network of two ideal diodes and three resistors as…2026asked 3×
• Briefly explain the two important processes that occur during the formation of a p-n junction.2026
• A semiconductor has equal electron and hole concentration of 3 × 10^8 m^-3. On doping with a certain impurity, the hole…2026
• Draw the V-I characteristics of silicon diode. Explain the following terms: (i) minority carrier injection in forward bias (ii)…2026
• With the help of circuit diagrams, briefly explain the forward biasing and the reverse biasing of a p-n junction diode.2026asked 3×
• Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output…2026asked 2×
• With the help of a circuit diagram, explain the working of a full wave rectifier. Depict the input and output waveforms.2026asked 3×
• A p-type or n-type semiconductor can be converted into a p-n junction by doping it with suitable impurity. The motion of majority…2026asked 3×
• Germanium crystal is doped at room temperature with a minute quantity of boron. The charge carriers in the doped semiconductors…2025asked 3×
• When the resistance measured between p and n ends of a p -n junction diode is high, it can act as a/an-2025asked 3×
• A p-n junction diode is forward biased. As a result,2025asked 3×
• When a p-n junction diode is forward biased2025asked 3×
• Assertion: n-type semiconductor is not negatively charged. Reason (R): Neutral pentavalent impurity atom doped in intrinsic…2025asked 3×
• Assertion: In a semiconductor diode the thickness of depletion layer is not fixed. Reason (R): Thickness of depletion layer in a…2025asked 3×
• Assertion: The impurities in p-type Si are not pentavalent atoms. Reason (R): The hole density in valance band in p -type…2025asked 3×
• Assertion: A hole is an apparent free particle with effective positive electronic charge. Reason ( R ): A hole is not necessarily…2025asked 3×
• Assertion: We cannot form a p-n junction diode by taking a slab of a p-type semiconductor and physically joining it to another…2025asked 3×
• In an intrinsic semiconductor, carrier's concentration is 5 × 10^8 m^-3. On doping with impurity atoms, the hole concentration…2025asked 3×
• Draw energy band diagrams of n -type and p-type semiconductors at temperature T 0 K. Show the donor/acceptor energy levels with…2025asked 3×
• A p-type Si semiconductor is made by doping an average of one dopant atom per 5 × 10^7 silicon atoms. If the number density of…2025asked 3×
• The threshold voltage of a silicon diode is 0.7 V. It is operated at this point by connecting the diode in series with a battery…2025asked 3×
• In an n-type semiconductor electron-hole combination is a continuous process at room temperature. Yet the electron concentration…2025asked 3×
• Draw the energy-band diagrams for conductors, semiconductors and insulators at T=0 K. How is an electron-hole pair formed in a…2025asked 3×
• Differentiate between half-wave and full-wave rectification. With the help of a circuit diagram, explain the working of a…2025asked 3×
• What are majority and minority charge carriers in an extrinsic semiconductor? A p-n junction is forward biased. Describe the…2025asked 3×
• What are majority and minority charge carriers of p-type and n-type semiconductors? Explain briefly the formation of diffusion…2025asked 3×
• Explain the process of formation of 'depletion layer' and 'potential barrier' in a p-n junction region of a diode, with the help…2025asked 3×
• Draw circuit arrangement for studying V-I characteristics of a p-n junction diode. Show the shape of the characteristics of a…2025asked 3×
• Extrinsic semiconductors are made by doping pure or intrinsic semiconductors with suitable impurity. There are two type of…2025asked 2×
• Extrinsic semiconductors are made by doping pure or intrinsic semiconductors with suitable impurity. There are two type of…2025
• Ge is doped with As. Due to doping,2024asked 3×
• An n-type semiconducting Si is obtained by doping intrinsic Si with:2024asked 3×
• A pure Si crystal having 5 × 10^28 atoms m^-3 is dopped with 1 ppm concentration of antimony. If the concentration of holes in…2024asked 3×
• When a p-n junction diode is subjected to reverse biasing:2024asked 3×
• Si is doped with a pentavalent element. The energy required to set the additional electron free is about:2024asked 3×
• Assertion: In a semiconductor, the electrons in the conduction band have lesser energy than those in the valence band. Reason ( R…2024asked 3×
• How does the energy gap of an intrinsic semiconductor effectively change when doped with a trivalent impurity, and pentavalent…2024asked 3×
• Suppose a pure Si crystal has 5 × 10^28 atoms m^-3. It is doped by 1 ppm concentration of boron. Calculate the concentration of…2024asked 3×
• How does the conductivity of an intrinsic semiconductor vary with temperature? Explain. Show the variation in a plot.2024
• Differentiate between 'diffusion current' and 'drift current'. Explain their role in the formation of p-n junction.2024
• Explain the characteristics of a p-n junction diode that makes it suitable for its use as a rectifier. With the help of a circuit…2024asked 3×
• Draw the circuit diagrams for obtaining the V-I characteristics of a p-n junction diode. Explain briefly the salient features of…2024asked 2×
• Explain the following, giving reasons: A doped semiconductor is electrically neutral. In a p-n junction under equilibrium, there…2024asked 3×
• Draw the circuit diagrams for obtaining the V-I characteristics of a p-n junction diode. Explain briefly the salient features of…2024
• Junction Diode as a Rectifier: The process of conversion of an ac voltage into a dc voltage is called rectification and the…2024asked 3×
• A pure semiconductor like Ge or Si, when doped with a small amount of suitable impurity, becomes an extrinsic semiconductor. In…2024asked 3×
• At a certain temperature in an intrinsic semiconductor, the electrons and holes concentration is 1.5 × 10^16 m^-3. When it is…2023asked 3×
• A semiconductor device is connected in series with a battery, an ammeter and a resisitor. A current flows in the circuit. If the…2023
• At 0 K, the resistivity of an intrinsic semiconductor is:2023
• For the forward biasing of a p-n junction diode, which of the following statements is not correct?2023
• Which one of the following elements will require the highest energy to take out an electron from them? Pb, Ge, C and Si2023
• During the formation of a p-n junction.2023
• The energy required by an electron to jump the forbidden band in silicon at room temperature is about2023
• During the formation of a p-n junction:2023
• The threshold voltage for a p-n junction diode used in the circuit is 0 · 7 V. The type of biasing and current in the circuit are:2023asked 3×
• In an extrinsic semiconductor, the number density of holes is 4 × 10^20 m^-3. If the number density of intrinsic carriers is 1.2…2023asked 3×
• An ac source of voltage is connected in series with a p-n junction diode and a load resistor. The correct option for output…2023asked 3×
• If a p-n junction diode is reverse biased,2023
• When an intrinsic semiconductor is doped with a small amount of trivalent impurity, then:2023asked 3×
• In the energy-band diagram of n-type Si, the gap between the bottom of the conduction band E C and the donor energy level E D is…2023
• The formation of depletion region in a p-n junction diode is due to2023
• Assertion: The resistance of an intrinsic semiconductor decreases with increase in its temperature. Reason (R): The number of…2023asked 2×
• Assertion: In insulators, the forbidden gap is very large. Reason (R): The valence electrons in an atom of an insulator are very…2023
• Assertion: In 'n' type semiconductor, number density of electrons is greater than the number density of holes but the crystal…2023asked 3×
• How is the width of depletion layer of a p-n junction diode affected when it is (i) forward biased, and (ii) reverse biased?…2023
• With the help of a circuit diagram, explain how a full wave rectifier gives output rectified voltage corresponding to both halves…2023
• Differentiate between intrinsic and extrinsic semiconductors. OR Draw the circuit arrangement for studying the V-I…2023asked 3×
• Draw energy band diagram for an n -type and p -type semiconductor at T 0 K.2023asked 3×
• Explain the roles of diffusion current and drift current in the formation of the depletion layer in a p-n junction diode.2023
• Answer the following giving reasons: (i) A p-n junction diode is damaged by a strong current. (ii) Impurities are added in…2023asked 2×
• Draw a circuit diagram of a p-n junction diode in forward biasing, and reverse biasing. Draw the V-I characteristics for each…2023
• Briefly explain how the diffusion and drift currents contribute to the formation of potential barrier in a p-n junction diode.2023asked 3×
• Explain the property of a p-n junction which makes it suitable for rectifying alternating voltages. Differentiate between a…2023asked 3×
• Draw the circuit arrangement for studying V-I characteristics of a p-n junction diode in (i) forward biasing and (ii) reverse…2023asked 3×
• (i) A germanium crystal is doped with antimony. With the help of energy-band diagram, explain how the conductivity of the doped…2023asked 3×
• With the help of a circuit diagram, explain briefly how a p-n junction diode works as a half-wave rectifier.2022
• The V - I characteristics of a solar cell is shown in the figure. What do the points P and Q represent? Give the circuit diagram…2022
• What is meant by energy band gap in a solid? Draw the energy band diagrams for a conductor, an insulator and a semiconductor.2022asked 3×
• Explain the formation of depletion layer and barrier potential in a p-n junction diode.2022
• Explain the formation of depletion region in a p-n junction.2022asked 3×
• What is meant by doping of an intrinsic semiconductor? Name the two types of atoms used for doping of Ge / Si.2022
• Two crystals C 1 and C 2, made of pure silicon, are doped with arsenic and aluminium respectively. (i) Identify the extrinsic…2022
• Give two differences between a half wave rectifier and a full wave rectifier.2022
• Draw energy band diagrams of n-type and p-type semiconductors at temperature T 0K, depicting the donor and acceptor energy…2022asked 3×
• Name the device which converts an ac input signal into a dc output signal. Write the principle of working of the device.2022
• Briefly explain the working of a light emitting diode. Mention its two uses.2022
• Distinguish between intrinsic and extrinsic semiconductors. Although in an extrinsic semiconductor n e ≠ n h, yet it is…2022
• Why a photo-diode is operated in reverse bias whereas current in the forward bias is much larger than that in the reverse bias?…2022asked 3×
• Name the extrinsic semiconductors formed when a pure germanium is doped with (i) a trivalent and (ii) pentavalent impurity. Draw…2022
• Define barrier potential. Why does the thickness of the depletion layer in a p-n junction diode vary with increase in reverse…2022
• Explain the formation of the barrier potential in a p-n junction.2022asked 3×
• Write the characteristics of a p-n junction which make it suitable for rectification.2022
• Name the device which converts electrical energy into light energy. Write three advantages of the device.2022
• (i) Draw V-I characteristics of a p-n Junction diode. (ii) Differentiate between the threshold voltage and the breakdown voltage…2022asked 3×
• Answer the following, giving reason: The resistance of a p-n junction is low when it is forward biased and is high when it is…2022asked 3×
• Draw the energy band diagrams for conductors, semiconductors and insulators. Which band determines the electrical conductivity of…2022
• Briefly explain how emf is generated in a solar cell. Draw its I-V characteristics.2022asked 2×
• State the working principle of an LED. Write any two important advantages and two disadvantages of LED.2022asked 3×
• With the help of a circuit diagram, explain the working of a p-n junction diode as a full-wave rectifier. Also draw its input and…2022asked 6×

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