## How to crack UGC CSIR NET Physical Sciences ? How to prepare study schedule for it ?

If you are preparing for CSIR JRF/NET exam, you must be either interested in further research work or in the lectureship. In both cases, you must be having a deep interest in your field. This exam basically tests your general aptitude and your grip on Physics. The exam is of medium to high toughness level, but what makes it really hard is the handful number of selections each year. Therefore you have to prepare in a highly systematic manner to crack this examination. Following are some useful tips for the preparation for this exam :

1. Strengthen your basics: A strong 12th Mathematics and Physics background is highly required and you should be strong in the fundamentals of Physics. As you will be going for further research or teaching, if you lack fundamental knowledge, it will be good for nothing.
2. Time factor: Study at least 4–5 hours a day. Have a time table and equally distribute the time to all the topics. And remember that one cannot master all the topics. Therefore the topics you are not familiar with must not be taken in the starting. At least 6 months of hard work is required. So plan everything according to it.
3. Study material : Keep yourself updated about the syllabus and know what to study. There are so n numbers of books and you should be very strict about what and what not to study. You don’t just want to spend a lot of time in preparing a single topic by reading the whole book. A selective study saves a lot of time. If you are not sure about it, better take a correspondence course from any prestigious coaching institute.
4. Previous year papers: SOLVE AS MANY PAPERS AS YOU CAN. It will get you the idea of types of questions asked in the exam from various topics and tell you about the status of your preparation too. After each topic, solve as many problems as you can. But keep the time factor in your mind too.
5. Motivation: And always keep yourself motivated. Yes, this path is not an easy one, but of course, not today but tomorrow, you will get paid for what you do now. So just have faith in yourself, plan and achieve it.

## Design a Solar System for Homes

Learn to Design Solar System in Easy Steps & get Certified as Energy Literate for Free

I hope you and your family are healthy and safe. The world is facing an unprecedented crisis in the form of COVID-19, and we hope that you are taking all the precautions to stay safe.

I have made a series of videos to “Design a Solar System for Homes” that can be completed in less than 3 hours. A free certificate on successful completion will be provided to all the participants. Don’t miss this opportunity and become Energy Literate in 2 easy steps.

1. Watch the Course Videos
There are 15 videos available both in English and Hindi
- Watch in English - https://bit.ly/DesignSolarSystem
- Watch in Hindi - https://bit.ly/DesignSolarSystem-Hindi
- Subscribe to Solar News and Knowledge to get details of more such courses in future. Click here - https://bit.ly/Subscribe-SNN

2. Take the Quiz after watching the videos
- Take the Quiz here - https://forms.gle/SRhUVDYTGDbWK81V7
- There are in total 32 questions of 40 marks. You need to score at least 25 marks to be eligible for the certificate

The course does not require any technical background. Why don't you start right away? Do share it with others in your groups and networks too!

## Eletronics Lab Praticals

Sr NoTitleAction
1To study the Input V-I characteristics of Silicon control Rectifier (SCR)
with definite biasing and plot the curve between V and I

2To study the Input V-I characteristics of DIAC with positive biasing and
negative biasing plot the curve between V and I
3To study the V-I input Characteristic Unijunction Transistor (UJT)
4
To study the V-I Characteristic of TRIAC with positive and negative biasing
and plot the curve between V and I
5To study the phenomenon of holding current and latching current of TRIAC
6To study the Latching Current and Holding Current of Silicon control
Rectifier (SCR)
7To study the Application of Silicon Control Rectifier (SCR) in Alarm Circuit
8
9
15To observe the output waveform positive, negative and double diode clipper
16To study the clamping process and observe the shifting of DC lines
17To determine the plateau and optimal operating voltage of a Geiger Muller counterClick here
18To determine the relationship between the intensity of radiation and the distance between source and detector in Geiger Muller counterClick here
20Measurement of Numerical Aperture (NA) of optical fiber

## Aim

To study the Input V-I characteristics of Silicon control Rectifier (SCR)
with positive biasing and plot the curve between V and I

## Apparatus:

• NV 6530 SCR Characteristics Trainer
• 2 mm Patch cords

## Theory

An SCR is an acronym for silicon-controlled rectifier and is commonly referred to as a thyristor. It is a unidirectional semiconductor similar to a diode, which allows for current to flow in only one direction. It differs from a standard diode by having a third connection called a gate that controls when the SCR turns on. The gate signal is typically a voltage pulse
that will turn on the SCR and allow for it to conduct the current. The SCR will continue to stay on as long as it is forward biased, and the voltage across it is the proper polarity. To shut off the SCR, the voltage across it has to be reversed. They are typically found on AC circuits where the energy is continuously switching polarities. In an AC circuit, it is possible to control what portion of each half cycle is passed through the SCR by controlling the time of the gate pulse relative to zero crossings. Since current can only flow in one direction,
SCRs are also used in rectifying circuits where the AC voltage is converted to DC, such as in DC drive. These devices are typically used in high power applications.

## Basic three modes of operation of SCR are

#### Reverse blocking mode

A cathode is positive concerning anode with the gate open. SCR is in reverse bias, i.e., junction J1 and J3 in reverse bias J2 are in forwarding bias. The device act as two PN diode connected in series with the reverse voltage applied across it. Leakage current of the order of a milliampere or
microampere flows, this is off the state of SCR. If reverse voltage increases, then at critical breakdown level or reverse breakdown voltage (VBR), an avalanche occurs at J1 and J3 and reverse current growth rapidly, so more loss in SCR. This may lead to SCR damage because the junction temperature is increasing. The maximum working reverse voltage across SCR does not exceed VBR. If the applied reverse voltage across SCR < VBR, then the device offers high impedance in the opposite direction. SCR is treated as an open switch.

#### Forward blocking mode (off-state mode)

The anode is positive concerning cathode with the gate open.
SCR is forward bias, junction J1 and J3 is forward bias, and J2 is reverse bias.
Here small forward leakage current flow.
If forward voltage increases then J2 junction (rev. bias) will have avalanche
breakdown called forward break over voltage (VBO)
The maximum working forward voltage across SCR does not exceed VBO. If
forward voltage < VBO; SCR offers high impedance. Hence SCR is treated as
an open switch even though it is forward blocking mode.

#### Forward conduction mode (on-state mode)

If we want to bring SCR from forwarding blocking mode to forward conduction

mode there are two modes:

By exceeding the forward break over voltage (VBO).

By applying gate pulse between gate and cathode.

Then SCR is in on state and behaves like a closed switch.

## Circuit Diagram

1. Connect terminal-1 to terminal-4,terminal-2 to terminal-8 and terminal 3 to terminal 12  as shown in figure
2. Connect a voltmeter across terminal- 7 and 8 and Ammeter across terminal-9 and 10 as shown figure-2
3. Make short terminal 5 and 6
4. Rotate the knob P_1 and P_2 fully in counterclockwise
5. Switch ON the power supply.
6. Set the value of Anode current I_g gradually by varying knob P_2 and observe it
7. Now Increases gate current I_g gradually by changing knob P_2 and keep it.
8. At a particular value of gate current, voltmeter reading falls down to almost zero. This action indicates the firing of SCR.
9. Note the gate current value at this position
10. Keep the gate current constant by shorting terminal 9 with 10 and connect Ammeter to the 5 and 6 ( figure 3)
11. Rotate the potentiometer P_1 fully counterclockwise.
12. Rotate knob P_1 (from the initial position to its maximum limit )gradually and record Anode current for the respective value of anode voltages
13.Plot the graph between anode voltage V_a and anode current I_a

## Observation Table

Gate current I_g = 7.5 mA

Sr NoAnode VoltageAnode Current (mA)
10.5 V0 mA
21.1 V1.2 mA
31.7 V1.3 mA
41.9 V1.3 mA
52.0 V1.5 mA
62.5 V1.5 mA
72.7 V1.6 mA
82.8 V3.0 mA
90.8 V36.5 mA
100.8 V41

## Result

Hence, Verify the Silicon Control Rectifier Voltage versus Current Characteristic

The MyePhysics is the Technical Platform which provides various tech supports for physics students like Class material, test series, events, and conference news

Creating awareness through social media platforms
Make a physics community

### Selection procedure:

Any physics students are eligible to apply. Selection will be done on the basis of Prior participation in extracurricular activities followed by a registration form.

### Rewards

This is a volunteer base platform we provide Certificate of appreciation
Last date of Registration:- 3 May, 2020
for more details call on- myephysics@gmail.com

Registration form:- Apply Now

## Webinar on observational and theoretical Astronomy

Dear All,
Webinar on observational and theoretical Astronomy "#VYOM" will be organized by Astronomy Club of St.Xavier college ( Astronomica); Department of Physics and Electronics; st. Xavier's College and Essence Tech. This webinar is exclusively predesigned for UG/PG Students/ Research scholars/Physics Educators/ Astronomy Loving Persons. This webinar will be organized from 12th April to 14th April 2020. For registration and further details pl refer to the following link and poster.

## Course Description

This course will cover some basic principles of Physics and will describe them through a few simple experiments. Sometimes the phenomena will be shown first, then in order to understand and analyze it, the theory will be explained. In some cases, it will be the reverse.

### Highlights

• This will be a 24 hours course spread over a period of 2 months.
• Each lecture will have 2-4 physics experiments followed by detailed explanations
• Most of the experiments can be assembled and performed by even a child of age group 13 years onwards
• The explanation part may be at the level of Plus 2 and in some cases above that
• The course SHARP can be taken by school students of Std 9 onwards, college students, Physics teachers and others interested in enjoying Physics.

### Methodology

• To do this online course one just need a Desktop/Laptop/Tablet/Mobile phone with an internet connection
• 3 lectures will be uploaded per week on the course website
• Students can ask questions to Dr. H. C. Verma by texting on the mobile phone.
• Replies can also be given by the fellow participants
• Based on your attendance (viewing of full lectures from the course platform) certificates will be given by CCE IIT Kanpur.

## Course Content

Optics
 Shadows and rectilinear motion Diffraction and Interference Polarization Scattering Reflection Fermat’s Principle Refraction Dispersion Prisms and Lenses
Mechanics
 Classification of forces Non-inertial frames and pseudo forces Rotating frames, Centrifugal, and Coriolis force Friction and Card-Coin experiment Rolling Angular momentum, Moment of inertia, Rigid body rotation Conical Pendulum
Electricity/Magnetism
 The circular motion of charge in a magnetic field Force on a current in a magnetic field B-field of a bar magnet and forces on a magnetic material in this field Misconceptions on poles Role of inhomogeneity in force on a magnet Diamagnetic and paramagnetic materials Curie Temperature Faraday’s law of induction Non-conservative Electric Field Lenz’s law and eddy currents
Oscillations and waves
 Stable equilibrium and oscillations Damped / Forced oscillations The similarity between mechanical and L-C-R oscillations Resonance The complexity of Simple pendulum Waves on a slinky, a string Wave speed, dependence on tension and linear density Standing waves on strings and on springs

## Course Audience

The discussion will be roughly at +2 and UG first-year level but the experiments could be an educative experience for students from grade 9 onwards. Most of these experiments will throw some challenges to understand it, so even the well-trained persons up to the Postgraduate level will find it interesting!
Core target groups are
(a)  Physics teachers teaching in schools from grade 9 to 12
(b)  Physics teachers teaching in colleges at B Sc, B.Tech level
(c)  Students from grade 9 to BSc/B.Tech
(d)  Others interested in enjoying Physics displayed by Nature in day-to-day life

Participants will be given certificates from the Centre for Continuing Education (CCE), IIT Kanpur, depending on the attendance.

## Physics Training and Talent Search (PTTS)

For Level-1: B.Sc. II /Int. M.Sc. II Year For
Level-2: M.Sc. I year /Int. M.Sc. IV year

WHEN: May 25 - June 15, 2020.

VENUE: Dept of Physics, Manipal Institute of Technology, Manipal Academy of Higher Education, Udupi-576104 Karnataka.

Every working day, there will be lectures and tutorials and a laboratory session on Experimental Physics. There will be guest lectures by eminent scientists. The methodology of training: Unlike in traditional lectures, in this program, classes will be interactive in nature. Tutorials will include discussing and solving problems. The experimental physics course will be structured to help you propose and design an experiment.

#### Selection Process:

50 students for level-1 and 35 students for level-2 will be selected from all over India. Selection will be based on your answer to the question in the online application, the recommendation from your teacher and academic performance in school/college. Performance in any standard examination such as NGPE, NTSE, and KVPY   will also be considered.
To create a diverse group of students we will try to represent, equally, female and male students from across various states in India, from rural and urban institutions. Merit will be the primary criteria for consideration. A few highly motivated BTech.(II year) students can also apply for Level-1. Few exceptionally bright students from a lower class can also apply.

#### HOW TO APPLY:

1. Fill in the online application form at the site:  https://www.ptts.org.in/
2. The Recommendation Letter can also be ﬁlled online by anyone who knows you well academically.
3. Answer the question that is given in the online application form and upload the solution.

Travel and accommodation: Students will be provided to and fro AC II-Tier train fare from residence/institution to Udupi Free boarding and lodging will be provided at Manipal Institute of Technology, Manipal, Participants will receive a certiﬁcate and resource materials on successful completion of the program. A few among those who perform well in the program will be considered for internships

FUNDED BY THE INFOSYS SCIENCE FOUNDATION

## Summer Internship in IISER and other National Institute

NameDurationLast Date of ApplicationStipendApplyResult
IISER Pune4-8 WeeksComing soonRs. 6000 per MonthApplyComing soon
IISER Mohali2 MonthsMarch 05, 2020 Coming soonApplyComing soon
IISER KolkataComing soonComing soonComing soonComing soonComing soon
IISER ThiruvananthapuramComing soonComing soonComing soonComing soonComing soon
IISER BhopalComing soonComing soonRs.3000 per month +AccomationComing soonComing soon
IISER TirupatiComing soonComing soonComing soonComing soonComing soon
FOSSEE IIT Bombay6-8 WeeksFebruary 25, 2020
ApplyMid-April 2020
TIFR 2 MonthsJanuary 31,2020Rs1555 per weekApplyFebruary 2020
SN Bose8 WeeksMarch 25,2020Rs.2000 per week + Travel costApplyApril 2020