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# Yearly Archives: 2015

## Remembering Verghese Kurien “Father of White Revolution in India”

Today 26 November 2015 is the 94th birthday of Verghese Kurien popularly known as “Father of White Revolution in India”. He founded around 30 institutions of excellence (like AMUL, GCMMF, IRMA, NDDB) which are owned, managed by farmers and run by professionals. As the founding chairman of the Gujarat Co-operative Milk Marketing Federation (GCMMF), Kurien was responsible for the creation and success of the Amul brand of dairy products.

Google celebrated the 94th birthday of Verghese Kurien by this doodle

Get more details here

## mechanical propertices in solids

Why the force of repulsion responsible for formation of solids and not the force of attraction ?

Dear Mayuri,

the question is not clear. Please explain further

## YDSE (Young’s Double Slit Experiment)

In the question we have a simple YDSE setup , there’s just the addition of a glass slab of thickness t and ,refractive index u, in front of the top slit ( S1). Now we submerge the entire setup into water (given refractive index u1). We now have to find the locations of the points, which are the points of constructive interference( max intensity).

I considered 3 approaches, first-

I calculated the optical path difference in water = t(u/u1 -1)- yd/D. where y is the reference coordinate of the maxima( any general position) from the original central maxima, d is the slit separation , and D is the distance from screen. For constructive interference path difference = n*wavelength( in water). Now wavelength in water= “wavelength in air”/u1 Therefore we get our answer.

Approach two:

I found out the path difference in water and multiplied it by u1 , to get the path difference in air , and I got the same result when I equated this path difference to- n*wavelength(in air).

Approach three- I found the path difference in air – t(u-1)-yd/D and divided this by u1, to get path difference in water, and equated this to n* wavelength (water). This time around , I did not get the answer.

Can anyone explain the difference between the second and third approaches. And also please do tell me, if I have committed some error.

Posted by Garvit Sharma

## Score More in Physics without fear – A Physics teacher’s advice

When I interacted with students of class 11 and 12, I came to know that Physics is one of the subjects they FEAR most during exam time. Though it seems difficult to score high marks, it is not actually so. Here are some suggestions you can easily follow to score more in Physics without much strain.

“Nobody plans to fail, but plans to fail”

Yes, A well planned study habit is essential to score more.

If you analyse the pattern of exam in class XI and XII (CBSE) the most of the marks are distributed among 3 marks questions and 5 marks questions which emphasizes the knowledge of concepts. SO, if you find it difficult to pass, then the following plan of action will easily work out.

• Identify all portions from which 5 marks questions can be asked and practice them well.
• Identify all portions from which three marks questions can be asked and practice them well.
• Learn all Laws, definitions, principles
• Practice all diagrams.
• Practice all solved problems given in text

http://cbsephysics.in/must-practice-questions-for-cbse-physics-class-12-solved/

http://www.plustwophysics.com/set-of-must-practice-questions-for-cbse-physics-class-xii-aissce-physics-2011/

Just try this routine and see whether you are scoring more or not.

For those already got pass marks can also try the above to better plus

• Solve all exercises and additional exercises from NCERT Textbook.
• Get a collection of all one marks questions and Two marks questions preferably from previous ten years’ question papers and find answers to them.

Those who want to excel further and look forward to entrance examinations, IIT, MBBS etc the following links to books will help.

## Interesting Question

If an object (for eg: consider a rod it may be iron or glass anything else) that has its own trust (automatic) for displacement. When it moves in the air in a direction with a constant speed of 100 kmph (Assume). When it traveling in its path, is it can raise upward?  Or it will change its direction automatically?

## Newton’s Laws of Motion

Suppose two blocks are placed in contact on a incline of some angle. They are under the action of only gravitational force and frictional force with each block having its own coefficient of friction. Now will they move down as a system in whole or will they split up with each having their own accelerations?

## from current electricity

Please check if i am right that when a current goes in a resistor it does not go swiftly out but drifts and equal current comes out the potential energy of the charges of the current converts into heat energy and less potential energy is left with the charges

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