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Eggs unboiled…..

My Dear Students

It is perhaps the time to recall what Sir Arthur C. Clarke; the famous science fiction writer said years back.

“When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong”.

Eggs unboiled……..

Impossible…Not really…Read on…….

The news item I came across yesterday sounded strange & hence worth-sharing…

The scientists have been able to unboil an egg….

The researchers boiled an egg for 20 minutes, before focusing on returning one protein in the egg white to its previous state. The idea was to combat the difficulties that arise when proteins “misfold”, forcing scientists to use time-consuming methods to untangle misfolded proteins or expensive methods to ensure the proteins don’t get tangled up in the first place.

It is believed that the findings could dramatically reduce costs in processes as far apart as cheese manufacturing and cancer research……For detailed news click below…..

http://www.theguardian.com/lifeandstyle/shortcuts/2015/jan/27/scientists-found-way-to-unboil-egg-proteins-cancer-research

Happy reading!

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हार्दिक शुभकामना……….Republic Day Greetings……….

हार्दिक शुभकामना……….

Happy Republic Day to all the Indians…

Let Every Teacher Teach
The Student How To Love This Nation,
Let Every Parent Instill
In His Or Her Sons And Daughters
The Beauty Of Our Nation…

Jamane bhar mein milte hain aashiq kayi
Magar vatan se khubsurat koi sanam nahi hota ,
Noto mein lipat kar, sone mein simat kar mare hain kayi ,
Mager tirange se khubsurat koi khafan nahi hota…

हार्दिक शुभकामना……….
Happy Republic Day to all the Indians…

हार्दिक शुभकामना

सरस्वती नामस्तुभ्यं,
वरदे कामरूपिणी!
विध्यारम्भं करिष्यामि,
सिद्धिर भवतु मे सर्वदा.
वसंत ऋतु के पावन पर्व पर आपको और
आपके परिवार को ढेरो शुभकामनाये।।
बसंत पंचमी २०१५ की हार्दिक शुभकामना ।। 

May the Goddess of Knowledge shower her

choicest blessings

on 

you n your family.

Happy Basant Panchami!

Examination 2015: Countdown begins…..III (Practicals).

Examination 2015: The Countdown Begins……III

The examination season has begun. The first crucial stage of C.B.S.E examination is the practical examination which must be on now or round the corner and would probably be over by 15th February 2015. This period offers you with a golden opportunity to prepare a few topics for the theory examination as well. The practical syllabus has 3 parts–

1.      Electricity

2.      Ray Optics

3.      Semiconductors

So before you go in for your practical examination, prepare these topics well.

Viva-voce questions for the three parts are being posted for you.

My personal experience over various years has shown that a large no. of students fail to perform well in Viva-voce even if they know the answers because they can’t express themselves.

So I would advise you to make a group (of students) if you have not done so far. Plan preparation and discuss the questions with each other. This will give you much needed practice and confidence to express yourself when you actually go for the viva; an important part of the practical examination.

Here are the questions for you:

Viva-voce- Electricity

Important diagrams:

  • Meter bridge
  • Potentiometer circuits
  • Conversion of galvanometer to ammeter & voltmeter

Viva-voce- Ray Optics

Important diagrams for this sub-unit

  • Ray diagrams for image formation by concave/convex mirrors and lenses
  • Path of light ray through prism (Derive relevant relations and memorise them)

Viva-Voce – Semiconductors 

Important diagrams for this sub-unit

  • Symbols of different types of diodes : pn junction, zener diode,LED etc.
  • Forward & Reverse biasing
  • Circuit for study of forward  & reverse characteristics of pn junction
  • Circuit for study of reverse ch of zener diode
  • Symbols of pnp and npn transistor
  • Circuit for study of characteristic curves of transistor in common emitter mode

It is also advisable to practice diagrams for half wave & full wave rectifier. The theory should be carefully prepared if the project you selected is based on electronic devices.

Needless to say that the practice will help you in CBSE theory exams well.

Remain relaxed when you are called for viva. Most of the examiners are friendly and will try to get the best out of you.

So get started.

HAPPY LEARNING!

All About Communication Systems……

Dear  Students,

It gives me pleasure to note that the series ‘ALL ABOUT…..’ clubbing the posts for every single Unit started a few days back with All About Electrostatics….as the first post was well received & appreciated.

Taking impetus from the response,a number of other units have also been clubbed.

The present ‘ALL ABOUT…..’ series by the author in ‘physicsbeckons’  is in line with our aim  to help you learn ‘Physics without fear’.

Here is ALL ABOUT Communication Systems for you…..

This unit in the CBSE class 12 syllabus carries about 5 marks and has a special advantage that generally direct questions are asked in this unit. The numerical problems in this unit are also very simple.

*The Videos

To be posted later

*The notes

Communication Systems-I

Communication Systems-II

Communication Systems-III

*The Assignment

Communication Systems

It is advisable to reinforce learning in the unit by trying to solve problems from Previous year papers.

Happy Learning!

All About Atoms & Nuclei………

Dear  Students,

It gives me pleasure to note that the series ‘ALL ABOUT…..’ clubbing the posts for every single Unit started a few days back with All About Electrostatics….as the first post was well received & appreciated.

Taking impetus from the response,a number of other units have also been clubbed.

The present ‘ALL ABOUT…..’ series by the author in ‘physicsbeckons’  is in line with our aim  to help you learn ‘Physics without fear’.

Here is ALL ABOUT Atoms & Nuclei for you…..

*The Videos

ATOMS & NUCLEI-I   (Thomson & Rutherford models of atom, their success and drawbacks, Alpha particle scattering experiment).

ATOMS & NUCLEI-II     ( Bohr’s theory of hydrogen atom, Expressions for orbital radii, orbital speed of the electrons &  Electron energy in different orbits of hydrogen atom. ).

ATOMS & NUCLEI-III    (Emission of spectral series in hydrogen atom)

*The notes

ATOMS & NUCLEI   

To be posted shortly

ATOMS & NUCLEI

Sample problems

*The Assignment

ATOMS & NUCLEI

To be posted shortly

It is advisable to reinforce learning in the unit by trying to solve problems from Previous year papers.

Happy Learning!

Examination 2015: The Countdown Begins……II

Dear Students

Hope your Pre-Board exams are over & you have received the results…….

Congrats to all who have done well & if you have not; here is an assurance that there is no reason for despair.

Leave the results of the pre-boards behind.

Now is the time to look ahead and prepare yourself for Physics. If you are worried about the subject; just do not panic.

Here are a few tips…

Visit MLL (Minimum Level of Learning) in the blog and download the same. It is a list of important topics which you must learn to get through.

Initially; don’t worry about your weak areas in the subject. Concentrate on your strong areas and reinforce the same.

Easy things first…. Learn the lessons which are very easy. That will give you the much-neede confidence.

The chapters, I would classify as simple and easy to learn with approximate marks allotted to each are:

EMW….3 marks

Communication systems…5marks

Value based questions…2 to 3 marks

Current Electricity…7 marks

Electronic devices… 7 marks

Dual nature of matter and readiations …4 marks.

Learn 5 marks questions from the previous years CBSE papers because they are often repeated.

You will find a fair number of solved papers in this blog.

Plan a schedule for study & Work on the plan.

The schedule should have a judicious mix of the study hours and the break/relaxation time. Don’t study for too long hours at a stretch. Give yourself  a gap. But make sure to return to the study table after the gap. This is very important. In addition:

  • Take care of your diet; it is essential to keep your energy level high.
  •  Remain focused and relaxed during preparation. Avoid nervousness.
  • Seek help when you need. Your teachers, parents & even friends can help. This may however need some planning.
  • Meditation & light exercises will be of great help for both body  & mind.

Keep yourself calm. Remember: It is most important for you & you alone. Don’t lose temper if you are advised to study longer by the parents. Frayed tempers would harm you & you alone.

Remember….It is your future which is at stake. 

Work with the confidence that a grand success awaits you.

Happy learning and best wishes!

All the CBSE Papers……..

Dear friends,

With the number of posts in the blog growing, I revisited the posts and decided to classify & club the posts pertaining to a unit in a single post. This will facilitate learning & make it enjoyable. The first post clubbed the information about the unit on Electrostatics followed by a few other units: Current Electricity; Dual Nature of Matter & Radiation & Wave Optics.

In continuation thereof; here is a post with All the CBSE Papers…. clubbed for you…..

PLEASE FEEL FREE TO PROVIDE ANY USEFUL CRITICAL INPUT ABOUT THE POSTS/BLOG.

PHYSICS SAMPLE PAPER 2015 Examination

SAMPLE PAPER for 2015

COMPLETE SOLUTION TO CBSE SAMPLE PAPER FOR 2015

Marking scheme

PHYSICS SAMPLE PAPER 2014 Examination

 SAMPLE PAPER for 2014

CBSE PAPER

Foreign-2013  (Solved)

Important topics covered: Transistor Characteristics, Zener diode as a Voltage regulator, Intrinsic & Impurity semiconductors, Diffraction at a single slit, Lens Makers’ Formula, Brewster’s law, Mutual inductance, Series LCR Circuit, Meter bridge, Compound Microscope, Refracting & reflecting type telescope, Radioactive Decay Law, Alpha particle scattering, Energy stored in a capacitor, Compound microscope.

CBSE PAPER

AI 2012    (Solved)

Important topics covered: Interference of light; Polarisation by reflection; Magnetic dipole moment of a current carrying coil; Conversion of galvanometer to ammeter and voltmeter; Relation between current and drift velocity; Equation for photo-electric effect; Energy stored in a capacitor; Reflecting type telescope; Work done in rotating an electric dipole in electric field.

CBSE PAPER

Delhi -2012    (Solved)

Important topics covered: Interference of light (need of coherent sources); Diffraction of light; Full wave rectifier; transistor amplifier; Van de graaff generator; Field due to a large flat sheet of charge using Gauss theorem; Need of modulation; nuclear density; Bohr’s theory; Energy stored in an inductor; Analog and digital signals; transducer; repeater in communication system.

CBSE PAPER

All India-2011    (Solved)

Important topics covered: Interference, Diffraction, AC generator, Moving Coil Galvanometer, Solenoid, Toroid, Full Wave Rectifier, Binding Energy curve, Displacement Current, Force between Current carrying conductors.

CBSE PAPER

Delhi-2011    (Solved)

Important topics covered: Young’s Double slit Experiment, Laws of Refraction (Huygen Principle), Polarisation of Light, Lens Makers’ Formula, Prism Formula, Total Internal Reflection, Magnification by Spherical Mirror, Cyclotron, Biot Savart Law, Transfomer, Series LCR Circuit Propagation of EM Waves, Radioactive Decay Law, Drift velocity, Gauss Theorem, Zener diode as a Voltage regulator.

CBSE PAPER

AII India- 2010    (Solved)

Important Topics Covered: Moving Coil Galvanometer: its conversion to ammeter and voltmeter, Transformer, Faraday’s laws,LED, pn junction characteristics, Telescope,Microscope.

CBSE PAPER

Delhi-2010    (Solved)

Important Topics Covered: Transistor as an Oscillator, Difference between Conductors, Insulators & Semiconductors, Diffraction at a single slit, Compound miroscope, Series LCR Circuit, Potentiometer, Photo diode, Radioactive Decay Law, Energy stored in a capacitor

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All About ELECTROMAGNETIC WAVES…………

Dear friends,

With the number of posts in the blog growing, I revisited the posts and decided to classify & club the posts pertaining to a unit in a single post. This will facilitate learning & make it enjoyable.The first post clubbed the information about the unit on Electrostatics followed by a few other units: Current Electricity; Dual Nature of Matter & Radiation & Wave Optics.

In continuation thereof; here is All About ELECTROMAGNETIC WAVES for you…..

PLEASE FEEL FREE TO PROVIDE ANY USEFUL CRITICAL INPUT ABOUT THE POSTS/BLOG.

All About  ELECTROMAGNETIC WAVES

*Minimum Level of learning in ELECTROMAGNETIC WAVES

As this is a very small & easy to understand unit in CBSE Class XII Physics, it is advisable to prepare it thoroughly. In general the questions asked are also direct.So with a little effort; all the three marks may be up for grab.

*The Videos

ELECTROMAGNETIC WAVES-I   (Introduction of Displacement Current; Equality of Conduction & Displacement Currents).

ELECTROMAGNETIC WAVES-II     (Maxwell’s equations; Prediction of E M Waves; Expressions for wave velocity Representation of EM waves & Transverse character ).

ELECTROMAGNETIC WAVES-III    (Production of E M Waves; The Electromagnetic Wave Spectrum)

*The notes

ELECTROMAGNETIC WAVES   

*The Assignment

ELECTROMAGNETIC WAVES

To be posted shortly

It is advisable to revise the unit by trying to solve Previous year papers.

Happy Learning!

All About Current Electricity:…………

Dear friends,

With the number of posts in the blog growing, I revisited the posts and decided to classify & club the posts pertaining to a unit in a single post. This will facilitate learning & make it enjoyable.The earlier posts in the series clubbed the information about the unit on Electrostatics,Wave Optics & Electromagnetic Waves.

Here is All About Current Electricity for you…..

*The Videos

Current Electricity-1   (Introduction to Electric Current, Types of current, Simple numerical problems)

Current Electricity-2  (Mechanism of current flow, Expression for drift speed & relation with current )

Current Electricity-3    (Relation between drift speed & current, Ohm’s law, Resistance, Resistivity, Factors affecting resistance.)

Current Electricity-4    (Current Electricity: Numerical Problems)

Current Electricity-5    (Cell: The EMF, Internal resistance & terminal voltage)

Current Electricity-6    (Series & Parallel Combination of Resistances)

Current Electricity-7    (Combination of Cells)

Current Electricity-8    (Introduction to Kirchhoff’s Laws)

Current Electricity-9    (Wheatstone Bridge; Slide Wire/Meter Bridge, Determination of resistance & resistivity)

**The Notes

Current Electricity-I (Electric Current, Expression for drift speed & relation with current )

Current Electricity-II (Ohm’s law, Resistance, Resistivity & factors affecting resistance.)

Current Electricity-III (Electrical Measurements, Kirchhoff’s law,Meter bridge, Potentiometer)

***The Assignment

To be posted shortly…

Happy Learning!