11. A point source of light is placed 4 m below the surface of water of refractive index 5/3. The minimum diameter of a disc, which should be placed over the source, on the surface of water to cut off all light coming out of water is ?

10. Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index is 3/2 is ?

9. A beam of monochromatic light is refracted from vacuum into a medium of refractive index 1.5, the wavelength of refracted light will be ?

8. Green light of wavelength 5460 Å is incident on an air-glass interface. If the refractive index of glass is 1.5 , the wavelength of light in glass would be (c = 3 × $10^8$ $ms^−1$) ?

7. A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source 1. When the mirror is rotated through a small angle θ, the spot of the light is found to move through a distance y on the scale. The angle θ is given by ?

6. Match the corresponding entries of column-1 with column-2 (Where m is the magnification produced by the mirror) :

6. Match the corresponding entries of column-1 with column-2 (Where m is the magnification produced by the mirror) :

5. Two plane mirrors are inclined at $70^◦$ . A ray incident on one mirror at angle θ after reflection falls on second mirror and is reflected from there parallel to first mirror. The value of θ is ?

4. A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is ?

3. A person is six feet tall. How tall must a vertical mirror be if he is able to see his entire length ?

2. If two mirrors are kept inclined at $60^◦$ to each other and a body is placed at the middle, then total number of images formed is ?

1. Ray optics is valid, when characteristic dimensions are ?

CBSE NEET JEE Guidelines for Students and Parents

 

                                                              

Physics is a multi dimensional subject and has to be studied from many different aspects. The purpose of this website is to provide students of class 11, 12 and entrance exam preparers with high quality study materials and useful resources.

Guidelines and FAQs for Students:

For CBSE and State Board exam success: Steps 1, 2, 3 are compulsory. Step 4 good to do.

Step 1: Theory, Concepts, Derivations:
CBSE or State board text books, Handbooks, Chapterwise Study (Useful simulations and collection of videos provided here), Study Notes.

Step 2: Numerical Practice: Examples, Exercises.
Solve the Numerical from your text book. 

Step 3: Numerical Practice: Chapter wise past paper questions
 Any one of the publishers such as Arihant, MTG, XAM Idea.

For Entrance exam success: Steps 4, 5 are compulsory for NEET, JEE Main, VITEEE, Amrita AEEE, KVPY, CUET etc. Step 6 compulsory for IIT aspirants.

Step 4: Numerical Practice: 

Competency Based Questions, Exemplar Questions from NCERT website

Step 5: Numerical Practice: 

Chapterwise NEET Past paper Questions, Chapterwise JEE Main Past paper Questions. 

Chapterwise PDF downloads provided here. Arihant or MTG publications are good.

Step 6: Numerical Practice: 

JEE Advanced Past paper Questions, 

Practice questions from Concepts of Physics, HC Verma.

Above steps can be equally applied for other subjects such as Mathematics, Chemistry and Biology.

How much Physics should I do?
One hour of physics per day,

10 numerical problems per day, 

2 to 3 weeks per chapter, 

Approx. 100 problems per chapter,

Approx. 14 chapters in one year of class 11, 

Approx. 14 chapters in one year of class 12.

Do I need a teacher to learn Physics?

Starting from Galileo and then Newton, Faraday, Edison, Tesla, Einstein, CV Raman, we have some 400 years of Physics discoveries packed into two years of 11th, 12th and entrance exam preparation. You can study from your school teacher alone. It is possible. But most students will need a tutor to help you with your difficulties initially.

How to study Physics?

You can study Physics from everywhere. Sometimes from a teacher, sometimes from textbooks, handbooks, sometimes from videos and interactive simulations, sometimes from doing some simple experiments in your home or your school, sometimes from your friend, sometimes from solving numerical problems, sometimes from nature, sometimes while going in a car or train. Physics is all around you. You just have to keep your eyes open.

Physics and Mathematics?

Physics and Mathematics are like twin sisters. They always come together. While the first part of any numerical solving is formulating the problem using Physics concepts, the second part is always mathematical simplification using Drawings, Graphs, Algebra, Trigonometry, Differentiation, Integration, Vectors etc.

Newton was not able to solve some Physics problems and he had to invent a new stream of Mathematics called Integral Calculus.

Mathematics is the language of mother nature. Physics is all about studying the nature. That's why it was called as Natural Philosophy.

Why do I have to study Physics?

Physics is the foundation for all Engineering and Science majors in college such as Mechanical, Aeronautical, Electrical, Electronics, Structural, Nuclear Engineering, Architecture, Integrated M.Sc. Physics, Energy Physics, Applied Physics, Photonics, Reactor Physics, Biophysics etc.

Students with proper physics foundation, do very well in Engineering majors. Engineering is all about problem solving. So get used to physics problem solving if you are planning to get into Engineering.

I find Physics problems very difficult?

Everything is difficult, before it becomes easy. Just like any other skills such as swimming, driving, speaking new language, Physics is also difficult to begin with.

"Remember, no problem is difficult. Once you understand the theory, each problem will become easy." - Dr. H.C. Verma

I am afraid. I make lot of mistakes?

Newton has made lot of mistakes. Einstein has made lot of mistakes. The good news is we are all allowed to make mistakes and then correct them. It's the first step to arrive at a solution.

For the Love of Physics

The capacitance of a parallel plate capacitor with air as medium is 6μF. With the introduction of a dielectric medium, the capacitance becomes 30μF. The permittivity ?

Two identical capacitors C1 and C2 of equal capacitance are connected as shown in the circuit. Terminals a and b of the key k are connected to charge capacitor C1 using battery of emf V volt. Now disconnecting a and b the terminals b and c are connected. Due to this, what will be the percentage loss of energy ?

The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is ?

A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system ?

A capacitor of 2μF is charged as shown in the diagram. When the switch S is turned to position 2 , the percentage of its stored energy dissipated is ?

A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect ?

A parallel plate air capacitor has capacity ’ C ’ distance of separation between plates is ’ d ’ and potential difference ’ V ’ is applied between the plates. Force of attraction between the plates of the parallel plate air capacitor is ?

Two thin dielectric slabs of dielectric constants K1 and K2 ( K1 < K2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field ’E’ between the plates with distance ’d’ as measured from plate P is correctly shown by ?