Class 12th Physics Semiconductor Electronics: Materials NCERT Notes CBSE 2023

# Chapter 14 Semiconductor Electronics

Chapter 14 Physics Lesson 12 NCERT - "Semiconductor Electronics - Materials, Devices and Simple Circuits." The NCERT notes includes answers and charts for long and short types of questions. In physics, it's also important to draw correctly labeled diagrams for your answers to be effective.

CBSE Class 12 Physics Chapter 14 describes the classification of metals, conductors and semiconductors, internal and external semiconductors, p-n junctions, semiconductor diodes and other related topics. Students are advised to practice all the in-text questions to achieve good scores.

### Points to Remember

Students can go through the important points to revise during the final examination:

• Diode: (i) By changing the external applied voltage, junction barrier of p-n junction diode can be changed.
(ii) Diodes along with the help of a capacitor or a suitable filter, can rectify AC voltage to a DC voltage.
(iii) After a certain (breakdown) voltage, the current suddenly increases in a Zener diode. This property has been used to obtain voltage regulation.
(iv) Applications of diodes: Photodiodes, Solar cells, Light emitting diode and Diode Laser, etc.

• Logic gates: (i) NAND and NOR gates are known as universal gates.
(ii) Output for OR gate will be False only when both the inputs are False.
(iii) Output for AND gate will be True only when both the inputs are True.
(iv) NAND gate is combination of AND and NOT gates.
(v) NOR gate is combination of OR and NOT gates.

• Extrinsic semiconductor: (i) Semiconductors which are doped with some impurities are known as extrinsic semiconductors.
(ii) Extrinsic semiconductors are of two types: nn-type and pp-type.

### Topics and Sub-topics

Chapter 14 Physics for Grade 12 may seem difficult for students to understand, but with consistent practice, students can easily master the basic concepts. Students should practice as many questions as possible to master the subject. Vidyakul notes helps students decipher problems and systematically understand solutions.

In addition to the free NCERT notes, Vidyakul provides NCERT 3D videos, NCERT samples, and more to make your exam preparation easier.

Below is the list of important topics under Class 12 Physics Chapter 14:

 Sr. No. Topic Name Description 1. Comparision of Vacuum Tubes and Semiconductors 2. Energy Band Theory and Electrical Properties of Matter 3. Semiconductor Material 4. Extrinsic Semiconductor 5. P-N Junction and Semiconductor Diode 6. Application of Junction Diode as a Rectifier 7. Special Purpose P-N Junction Diodes

### Few Important Questions

• Who discovered the transistor?

John Bardeen, Walter Brattain and William Shockley invented the first working transistors at Bell Labs, the point-contact transistor in 1947.

• What are ‘Semiconductors’?

Semiconductors are substances with properties somewhere between them. ICs(integrated circuits) and electronic discrete components such as diodes and transistors are made of semiconductors.

• What is a ‘Bipolar junction’?

A Bipolar Junction Transistor is a solid-state device in which the current flow between two terminals (collector and emitter) is controlled by the amount of current that flows through a third terminal (base).

### Practice Questions

1. When a p-n junction is set to forward-biased,

1. we could witness a rise in the potential barrier.

2. we could see a reduction in the majority carrier current to the value zero.

3. there is a decrease in the potential barrier.

4. None

2. In transistor action, identify the correct statements.

1. The doping concentrations and size of the base, emitter, and collector are similar

2. The base region is found out to be thin and lightly doped

3. The collector junction and the emitter junction is reversed biased and forward biased respectively

4. Both the collector junction and the emitter junction are forward biased.