This document provides an overview of an alternating current (AC) generator. It includes sections on the principle, construction, theory of operation, circuit diagram, expression for induced electromotive force (emf), and applications. The key components of an AC generator are an armature coil that rotates in a magnetic field, slip rings to draw current from the rotating coil, and brushes that supply the output. As the coil rotates, the changing magnetic flux induces an alternating current in the coil. The maximum induced emf is expressed as ε = ε° sin(ωt). Applications include power generation and distribution, vehicles, appliances, and portable generators.
Rectifier class 12th physics investigatory projectndaashishk7781
Investigatory project of physics class 12 for helping kendriya vidyalaya students
Project on rectifier whoever taking this project also requires a modal of rectifier
Rectifier class 12th physics investigatory projectndaashishk7781
Investigatory project of physics class 12 for helping kendriya vidyalaya students
Project on rectifier whoever taking this project also requires a modal of rectifier
PHYSICS INVESTIGATORY PROJECT
AIM:-
CHARGING AND DISCHARGING OF CAPACITORS IN R-C CIRCUIT
PURPOSE
THE GOAL OF THIS PROJECT IS TO verify that 63% charge is stored in a capacitor in an R-C circuit at its time constant and 63% charge remains when capacitor is discharged and hence plot a graph between voltage and time
TOPIC-To investigate the relation between the ratio of :-1. Input and outpu...CHMURLIDHAR
TOPIC-To investigate the relation between the ratio of :-1. Input and output voltage.2. Number of turnings in the secondary coil and primary coil of a self made transformer.
Class 12 CBSE Biology Investigatory project on the topic "Drug Addiction" which includes the appropriate format and content for the CBSE practical examinations.
PHYSICS INVESTIGATORY PROJECT
AIM:-
CHARGING AND DISCHARGING OF CAPACITORS IN R-C CIRCUIT
PURPOSE
THE GOAL OF THIS PROJECT IS TO verify that 63% charge is stored in a capacitor in an R-C circuit at its time constant and 63% charge remains when capacitor is discharged and hence plot a graph between voltage and time
TOPIC-To investigate the relation between the ratio of :-1. Input and outpu...CHMURLIDHAR
TOPIC-To investigate the relation between the ratio of :-1. Input and output voltage.2. Number of turnings in the secondary coil and primary coil of a self made transformer.
Class 12 CBSE Biology Investigatory project on the topic "Drug Addiction" which includes the appropriate format and content for the CBSE practical examinations.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
A.c. generator
1.
2. Contents
Certificate
Acknowledgement
Introduction
Principle of A.C. Generator
Construction of A.C. Generator
Theory
Circuit Diagram
Working of A.C. Generator
Expression for Instaneous e.m.f. produced
Result
Applications of A.C. Generator
Bibliography
3. Certificate
This is to certify that Aditya Singh, a student of class
XII-A has successfully completed the project under the
guidance of Mr. Nitin Khabrani (Physics Teacher)
During the academic year 2016-17 in partial fulfillment of
chemistry practical examination conducted by CBSE,
New Delhi.
Signature of external examiner Signature of chemistry teacher
4. It would my utmost pleasure to express my
sincere thanks to my physics teacher
MR. NITIN KHABRANI in providing
a helping hand in this project.
His valuable guidance and support and
supervision all through this project are
responsible for attaining its present form.
Acknowledgement
5. Introduction
A.C. Generator means Alternating current generator. It is a
device which is used to convert mechanical energy into
electrical energy.
A.C. generator forces electric current to flow through an
external circuit. The source of mechanical energy may be a
reciprocating or turbine steam engine, water falling through
a turbine or waterwheel, an internal combustion engine,
a wind turbine, a hand crank, compressed air ,or any other
source of mechanical energy.
6. Principle of A.C. Generator
It is based on the principle of electro magnetic
induction, i.e., whenever amount of magnetic flux
linked with a coil changes, an e.m.f. is induced in the
coil. The direction of current induced is given by
Fleming’s right hand rule.
7. Construction of A.C. generator
The A.C. Generator is consist of four main parts :
(1) THE COIL (ARMATURE) :
A rectangular coil ABCD consist of a large number
of turns of copper bound over a soft iron core is called
armature. The soft iron core is used to increase the magnetic
flux.
(2) MAGNETIC FIELD :
It is usually a permanent sponge magnet having concave
poles. The armature is rotated of a magnet so that axis of the
armature is perpendicular to magnetic field lines.
8. (3) SLIP RINGS :
Slip rings are the magnetic rings which are connected
in the terminal of the armature. These rings are rotated
with the coil and these are use to draw the current from
the generator.
(4) BRUSHES :
The brushes B1 & B2 are just touch the slip rings. They are
not rotating with the coil and these brushes leads to the
output of load resistance.
9. Theory
1. The strong magnetic field is produced by a current flow through the
field coil of the rotor.
2. The field coil in the rotor receives excitation through the
use of slip rings and brushes.
3. Two brushes are spring-held in contact with the slip rings to provide the
continuous connection between the field coil and external circuit.
4. The armature is contained within the windings of the stator and is
connected to the output.
5. Each time the rotor makes one complete revolution, one complete
cycle of AC is developed.
6. A generator has many turns of wire wound into the slots of the rotor.
7. The magnitude of AC voltage generated by an AC generator is
dependent on the field strength and speed of the rotor.
8. Most generators are operated at a constant speed; therefore, the
generated voltage depends on field excitation, or strength.
11. Working of an A.C. Generator
The coil is rotated in anti-clock wise direction. In the first
half rotation the arm AB is moving outward and CD is
moving inward. So the e.m.f. is induced in the arm AB
from A to B. And in the arm CD from C to D. After half
rotation (in the second half). The arm CD is moving
outward and AB is moving inward. In this time current is
induced in arm CD from D to C. And in arm AB from B to
A. In the second half rotation the current direction is
changing so in this generator AC is produced.
12. Expression for Instaneous
e.m.f. produced
Let position of the coil at any time t. It's make angle θ with
vertical. If w is uniform angular speed
of the coil.
Then θ =ωt
B be the strength of magnetic field n be the number of
turns in the coil and A area of the coil then magnetic flux
with the coil in this position is given by :
Φ = nBA Cosθ = nBA Cos ωt.
13. differentiate w.r.t. time :-
𝑑∅
𝑑𝑡
=nBA
𝑑 cos(𝜔𝑡)
𝑑𝑥
𝑑∅
𝑑𝑡
= nBA-sin(𝜔𝑡)𝜔
𝑑∅
𝑑𝑡
= -nBA 𝜔 sin(𝜔𝑡)𝜔
ε=-
𝑑∅
𝑑𝑡
=-(-nBA 𝜔 sin(𝜔𝑡)𝜔)
Maximum value of e.m.f. say so 𝜺°
ε = ε° sin(𝜔𝑡)
14. Result :-
Hence, maximum value of instantaneous
e.m.f. in a AC Generator is given by
𝜺 = 𝜺° sin(𝝎𝒕)
15. Applications of A.C. Generator
1. Aircraft auxiliary power generation, wind generators,
high speed gas turbine generators.
2. Hybrid electric vehicle (HEV) drive systems, automotive
starter generators.
3. An ac generator, or 'alternator', is used to produce ac
voltages for transmission via the grid system or, locally,
as portable generators.
4. All of our household appliances runs on ac current.
Ex: Refrigerator, washing machines, oven, lights, fan etc.
5. The main advantage of AC is ease of power distribution.
It is more efficient to use high voltage to distribute power,
but it is not safe to have high voltage at home. It is easy to
step up (and step down) AC voltage using a transformer.
16. Bibliography
• CBSE Lab manual
• Help of Physics Teacher
• NCERT Textbook
• Websites:-
www.google.com
www.wikipedia.com