Semiconductor Electronics is a vital chapter in Class 12 Physics, providing a foundational understanding of modern electronic devices and their applications. This topic explores the principles of semiconductors, their types, and how they function in electronic systems. It lays the groundwork for advanced studies in electronics, communication, and technology, making it a crucial part of the curriculum.
One of the most effective ways to grasp the concepts of Semiconductor Electronics is through Multiple Choice Questions (MCQs). These questions not only test conceptual understanding but also enhance problem-solving skills and prepare students for competitive exams like JEE, NEET, and other entrance tests. The MCQ format allows students to quickly assess their knowledge and identify areas requiring improvement, helping them build a strong conceptual framework.
The chapter begins with the basics of semiconductors, such as their classification into intrinsic and extrinsic types, and progresses to key concepts like doping, the behavior of p-type and n-type semiconductors, and the energy band theory. Students learn about the significance of covalent bonding in semiconductors, the role of charge carriers (electrons and holes), and how the conductivity of semiconductors changes with temperature.
In addition to the theoretical aspects, the chapter emphasizes practical applications through discussions on essential devices like diodes, transistors, rectifiers, and logic gates. These devices form the building blocks of modern electronic systems, including computers, mobile phones, and other gadgets. Understanding their working principles helps students appreciate how theoretical concepts translate into real-world innovations.
MCQs based on Semiconductor Electronics cover a wide range of topics, from the fundamental properties of semiconductors to advanced applications of devices like transistors in amplification and switching. They often include questions on energy bands, junction diodes, rectifiers, and the impact of temperature on semiconductor properties. These questions not only reinforce theoretical knowledge but also improve analytical thinking and application-based understanding.
Preparing for Semiconductor Electronics MCQs enables students to approach the subject with clarity and confidence. It encourages them to think critically, connect concepts, and solve problems efficiently. With consistent practice, students can strengthen their understanding of this pivotal topic and excel in both board exams and competitive tests. By mastering the intricacies of Semiconductor Electronics, students open doors to exciting opportunities in science, engineering, and technology.
Class 12 Semiconductor Electronics MCQs
What type of bonds are found in semiconductors?
(a) Monovalent
(b) Bivalent
(c) Trivalent
(d) Covalent
Answer: (d) Covalent
Explanation: Semiconductors have covalent bonds.
How many electrons are present in the valence shell of a semiconductor?
(a) 1
(b) 2
(c) 3
(d) 4
Answer: (d) 4
Explanation: Semiconductors have 4 electrons in their valence shell.
What happens to the forbidden energy gap of a semiconductor when the temperature decreases?
(a) Decreases
(b) Increases
(c) Stays the same
(d) Sometimes increases, sometimes decreases
Answer: (b) Increases
Explanation: The energy gap widens as the temperature falls.
In a p-type semiconductor, conduction occurs due to:
(a) Holes
(b) Atoms
(c) Electrons
(d) Protons
Answer: (a) Holes
Explanation: In p-type semiconductors, holes are the primary charge carriers.
What is the main function of a transistor?
(a) Simplify
(b) Amplify
(c) Rectify
(d) All of the above
Answer: (b) Amplify
Explanation: Transistors are used to amplify signals.
Do Check: NCERT Exemplar for Class 12 Physics Chapter 14 – Semiconductor Electronics
What is responsible for conduction in a semiconductor?
(a) Only electrons
(b) Only holes
(c) Both electrons and holes
(d) Neither electrons nor holes
Answer: (c) Both electrons and holes
Explanation: Conduction in semiconductors is carried out by both electrons and holes.
What happens to the resistance of semiconductors when heated?
(a) Increases
(b) Decreases
(c) Remains unchanged
(d) First increases, then decreases
Answer: (b) Decreases
Explanation: Resistance in semiconductors decreases with an increase in temperature.
In intrinsic semiconductors at room temperature, the number of electrons and holes are:
(a) Unequal
(b) Equal
(c) Infinite
(d) Zero
Answer: (b) Equal
Explanation: Electrons and holes are equal in number in intrinsic semiconductors.
Which of the following is not a universal gate?
(a) NOT
(b) AND
(c) OR
(d) NAND
Answer: (d) NAND
Explanation: NAND is not considered a universal gate.
What is the charge of a p-type semiconductor?
(a) Positively charged
(b) Negatively charged
(c) Neutral
(d) Uncharged at 0K but charged at higher temperatures
Answer: (c) Neutral
Explanation: A p-type semiconductor is electrically neutral.
What is the resistivity of a pure semiconductor at absolute zero?
(a) Zero
(b) Infinity
(c) Similar to conductors at room temperature
(d) Similar to insulators at room temperature
Answer: (b) Infinity
Explanation: At absolute zero, semiconductors behave as perfect insulators.
In a p-n junction diode, forward biasing results in:
(a) Depletion region and barrier height reduction
(b) Depletion region widening but barrier height reduction
(c) Depletion region reduction but barrier height increase
(d) Both depletion region and barrier height increase
Answer: (a) Depletion region and barrier height reduction
Explanation: Forward bias reduces both the depletion region and the barrier height.
What is the purpose of a filter circuit?
(a) Removes AC components
(b) Removes DC components
(c) Retains AC components
(d) None of these
Answer: (a) Removes AC components
Explanation: Filter circuits eliminate AC components from a signal.
A bridge rectifier uses:
(a) Four diodes
(b) Six diodes
(c) Two diodes
(d) One diode
Answer: (a) Four diodes
Explanation: A bridge rectifier requires four diodes.
Do Check: NCERT Solutions for Class 12 Physics Chapter 14 Semiconductor Electronics
At room temperature, in semiconductors:
(a) Conduction band is empty
(b) Valence band is partially empty, and conduction band partially filled
(c) Valence band is completely filled, and conduction band is partially filled
(d) Valence band is completely filled
Answer: (c) Valence band is completely filled, and conduction band is partially filled
Explanation: At room temperature, some electrons move to the conduction band, leaving the valence band filled.
