What is nanotechnology?

Nanotechnology is the science of management and manipulation of atoms and molecules to design a new technology. Nanotechnology is the supramolecular technology, which means, it is the engineering of functional systems at the molecular or supramolecular scale.

Describe the experimental set up for obtaining output characteristic curve of a PNP transistor in common emitter configuration with suitable circuit diagram. Also draw the curve obtained. Select possible value of common base current amplification factor α of a transistor among the following. 0 . 9 , 9 , 19 , 49 and 99

Common emitter characteristics: The common emitter characteristics are the graphs drawn between appropriate voltages and currents for a transistor when its emitter is taken as the common terminal and grounded (zero potential), base is the input terminal and collector is the output terminal. The emitter-base junction is forward biased by means of battery V B B through rheostat R h 1 . The emitter collector circuit is reverse biased by means of battery V C C through rheostat R h 2 . The base-emitter voltage V B E and the collector-emitter-voltage V C E are measured by high resistance voltmeters. The base current I B . is measured by a micro ammeter and the collector current I C by a milliammeter. Input Characteristic : A graph showing the variation of base current IB with base-emitter voltage V B E at constant collector-emitter voltage V C E is called the input characteristic of the transistor. Two such curves for two different collector-emitter voltages have been plotted in fig. Output characteristic : A graph showing the variation of collector current I C with collector-emitter voltage V C E at constant base-current IB the output characteristic of the transistor. Fig. shows such curves for different values of I B . The possible value of common base current amplification factor α of a transistor is 0.9.

Select acceptor type impurity among the following: arsenic As , Antimony Sb , gallium Ga and phosphorous P .

Pentavalent impurity atoms have 5 valence electrons. The various examples of pentavalent impurity atoms includes Phosphorus (P), Arsenic (As), Antimony (Sb). These are N-type semiconductor when doped with pentavalent impurity elements. whereas, Gallium is Trivalent impurity or acceptor type impurity.Hence, when it is added to germanium(Ge) it will form P-type semiconductor.

Modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 14 - Semiconductor Electronics: Materials, Devices and Simple Circuits>Rajasthan Board-2019>Q 10

EASY

12th Rajasthan Board

IMPORTANT

Earn 100

Draw symbol of Zener diode.

Important Questions on Semiconductor Electronics: Materials, Devices and Simple Circuits

EASY

12th Rajasthan Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 14 - Semiconductor Electronics: Materials, Devices and Simple Circuits>Rajasthan Board-2018>Q 5

Draw circuit diagram for a $P - N$ junction to obtain reverse bias characteristic curves. Explain the phenomenon of reverse breakdown for a $P - N$ junction in reverse bias state by following process-

$(i)$ Avalanche breakdown

EASY

12th Rajasthan Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 14 - Semiconductor Electronics: Materials, Devices and Simple Circuits>Rajasthan Board-2018>Q 7

Draw circuit diagram for a

NPN -

transistor to obtain characteristic curves in common base configuration. Establish a relation between current amplification factors for a transistor in common base and common emitter configuration.

EASY

12th Rajasthan Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR PHYSICS>Chapter 14 - Semiconductor Electronics: Materials, Devices and Simple Circuits>Rajasthan Board-2019>Q 8

Write value of output $Y$ in diagram.

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