Thursday, March 29, 2012

Environmental Science Lab

Environmental Molecular Sciences

What is Environmental Science Lab?

Wikipedia says-
Environmental science is an interdisciplinary academic field that integrates physical and biological sciences, (including but not limited to Ecology, Physics, Chemistry, Biology, Soil Science, Geology, Atmospheric Science and Geography) to the study of the environment, and the solution of environmental problems. Environmental science provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems


In India Environmental studies is an integral Part of the Primary School Curriculum.

What is Physics 212 ?

Were you searching for Physics 212?

The following links will help you.
University of Illinois at Urbana–Champaign

Physics 212 is the Physics Course on Electricity and Magnetism by University of Illinois.

(Many other colleges and universities may have a couse by the same name but dealing with different topics in Physics.

The advantage of Physics212course of Illinois is that many course materials and animations etc are available online and can be used by any prospective student.
Ashley B. '12 | On The Road Again


Monday, March 26, 2012

Kerala HSE +1 Physics Exam is Over ! How was it?

Kerala HSE Plus One Physics Examination 2012 is over.
The political state of Kerala in India was cre...

How was the exam?

We will soon upload the question paper. By then you can discuss the questions and the answers.

Kerala is well known for the versatile structure of questions which checks the level of understanding of the student. Such questions will be a model for practice for all over the world.

Sunday, March 25, 2012

Why Physics Exams are always reported difficult every year?

It is commonly found that there are maximum complaints after the Physics Exam. What could be the reason?

The fact is that there are students scoring 100% even in this "reportedly toughest " question papers.

CBSE is also getting the questions prepared by Professors who are actively involved in text book preparations and with many years of experience. CBSE follow a standardized pattern for question papers too.

Even then after the Physics examination there is an uproar and requests are received from various parts regarding the faults and toughness of the question paper. The other subjects are not like this.

(See the posts and and )

  • Is this because the Physics is not taught the way it should be?

Many educational institutions are coming up every year. There is  a scarcity of teachers, especially in Physics. Some are taking the job just as a means to earn income. Many do not know and follow the pattern of CBSE but some how they manage to complete the portions.

In many schools, other refresher books are followed instead of the NCERT Text book. This creates lot of problems. The CBSE question paper is set based on the data given in NCERT Text book. If there is a confusion, what is given in NCERT text book will get weightage.

  • Or is it because the students are more after the competitive exams and they start capsulizing things without understanding the concepts?

Such students solve the numerical problems excellently but fail to solve understanding and skill based questions. The style of presentation is also very important.

Exams are killing me.

Now, it has become important to understand the concept and follow the textbook thoroughly to get admission to IITs and other courses as they have started counting the marks scored in  Exams too.

Or, are there some other problems which make Physics exam difficult year after year. Come on let's discuss.....

How was CBSE Maths?

Now that CBSE Maths exam is also over, comment on the question paper.

Was it easy, moderate or difficult?

Could you answer the questions in time?

Post the doubtful questions and discuss online ...


Friday, March 23, 2012

No need to worry over Physics (CBSE)

Students of Nan Hua High School gathering in t...

The evaluation of AISSCE 2012 Physics started and CBSE has prepared a fool proof marking scheme which will give the students the marks they deserve.

However, those who just left the questions unanswered will be at loss; because many of the difficult questions are liberalized but only those who attempted the questions will get the benefit.

Those questions with tougher subdivisions are so evaluated that the easier portions are given more marks than the difficult portions. So, if the students attempted the easier portion and left the difficult portion, the loss is not much.

So, relax!

Your voices are heard, thanks to CBSE for paying heed to us - the teachers and students.


CBSE Class XI Results show sharp decline since the introduction of CCE

Students, 2009 batch, at Class, Parisutham Ins...

The results of Class XI is shamefully low since the introduction of CCE in classes up to class X. The CCE ensures pass of every student. It is further emphasized that the student should get admission in the same school. This criteria make the students less responsible and they get good percentage in class X without much knowledge expected of that level.

The students mainly get good grades in formative assessments in which most of the activities are performed in groups. Almost all students of the group are getting almost identical marks and grades. So, even a weak student gets good grades because he is part of the group. These grades scored by him ensures his admission to science group in class XI. Only when the result of Class XI comes he realizes that he is not fit for the science group (or any other group he has chosen).

The teachers of class XI are more worried where the administration wants 100% result out of these students with little aptitude towards the subject. It is high time that the system be reviewed and ensure that only students with aptitude towards science steam come in Science group as well as other streams.

You responses in this regard are welcome. All students and teachers as well as parents are requested to take part in this discussion. Post your views and responses as comments to this post.

Thursday, March 22, 2012


Central Board of Secondary Education

The CBSE Results 2012for class X (AISSE) and class XII (AISSCE) will be published by the third week of May 2012.

For Class X, the CCE details are being uploaded by the Vidyalayas to CBSE server. The schools are given time till 15 April for updating the marks up to Summative Assessment 2 for Class X 2012.

The results will be published at

The results of both Board Based exams and School Based Exams will be published together.

Tuesday, March 20, 2012

How was CBSE Science Exam for Class X?

The preliminary examination of the All India P...

CBSE Science exam was today (20 March 2012).

How was the exam?

Many students reported that the exam was quite easy and could easily score 90% and above.

How was the Science exam for you?

Were there any errors in the question paper?

Were there any question out of syllabus?

Were the diagrams and other questions the expected ones?

Were there any questions beyond comprehension?

Respond now....

You can post the difficult and confusing questions as comments to this post and we'll discuss the solutions

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Download the Free Issue of Physics World Magazine

Click here to Download the Free Issue of Physics World Magazine.

This issue focuses on Physics and Earth


Monday, March 19, 2012

A few questions to students

Student teacher in China teaching children Eng...

Many teachers often say that, when students get good marks they claim to be because of their own effort and when they fail or get very less marks, they blame it own the teachers.

I want to ask this questions to students in open. Any student can join the discussion. Whatever you post, let it be your own genuine answer.

Here are the question for students.

If you get good marks in Physics, is it because of your teacher or because of your own effort?

If you don't  get good marks in Physics, is it because of your teacher or because of your own lack of practice?

Teachers are also welcomed to post their response.

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Tuesday, March 13, 2012

Did CBSE shock students in Chemistry too?

AISSCE Chemistry reported to be tough and different from previous years.

What's your opinion?

Post your reactions at CBSE Chemistry website

Class XI CBSE Chemistry Model Paper


Class – XI

Time – 3 Hrs. Marks – 70


General Instructions :

i) All questions are compulsory.

ii) Q. s 1 to 8 carry 1 makes each. Answer them in one word or in about on sentence.

iii) Q. s 9 to 18 carry 2 marks each. Answer these in about 30 words each.

iv) Q. s 19 to 27 carry 3 marks each. Answer these in about 40 words each.

v) Q. s 28 to 30 are long answer questions carrying 5 marks each.

vi) Use long table if necessary, use of calculator is not permitted.


1. Write IUPAC name of the following compound : 1


2. Write down the formula of the monomer of silicone. 1

3. What would be the effect of increasing pressure on the equilibrium. 1

PCl5 (g) = Pcl3 (g) + Cl2 (g) ?

4. What is the oxidation number of oxygen in Na2O2 ? 1

5. What would be the sign of S for the process 2H (g) à H2 (g) ? 1

6. What is compressibility factor of a gas ? 1

7. Configuration of ion M+2 is Is2 2s2 2p5 what is configuration of atom M? 1

8. How many oxygen atoms would be there in 1 mole of H2SO4 ?

9. clip_image004 a) What is the hybridization of each carbon in CH3 – CH2 ? 1

b) What is the function of AlCl3 (anhyd) in Friedel Crafts reaction ? 1

10. How N and S are detected when present in an organic compound together ? (Reaction only) 2


Which is the electrophillic centre in CH3Br and why ?

11. Why lithium does not form a superoxide but potassium does ? 2


Why BeSO4 is water soluble but BaSO4 is not ?

12. Balance the following redox feaction by ion 2

Electron method :

Cr2 O7-2 + Fe+2 à Fe+3 + Cr+3 in acidic medium.

13. a) What is the change in internal energy in a process in which 700J of heat is absorbed and 450J of work is done by the system ?

b) Define a spontaneous process in terms of Gibbs energy. 1

14. Show by MO concept which one out of O2 and O2+ would be more stable. 2


Explain all the orbital overlaps in a molecule of ethene (C2H4) by drawing a sutitable diagram.

15. Calculate the mass of (NH4)2 S required to prepare 200 ml of O.1 molar aqueous solution.

(N = 14, H = 1, S = 32)

16. a) Write down the IUPAC name and symbol of the element with at no 119. 1

b) Why Cl has more negative electron gain enthalpy then F in group 17 ? 1

17. Arrange the species : F-, O-2, N-3, Mg + 2, Al + 3 and Na+ in the increasing order of ionic radii and give reason. 2

18. Deduce the structural formula of an alkene which on ozonolysls produces propanal and pentanone – 2. 2

19. a) What is Eutrophication ? 1

b) How can photochemical smog be controlled ? 1

c) Give an example of herbicide. 1

20. a) Why atomic radius of Ga is less then the of Al in group 13 ? 1

b) Why white fumes appear around a bottle of anhydrous AlCl3 ? 1

c) Why Sn+2 is a reducing agent but Pb+2 is not ? 1

21. Determine the percentage of Nitrogen in an organic compound, 0.5g of which on kjeldalisation required 10ml of 1M. H2SO4 for complete neuteralisation of the ammonia produced. 3


What is the percentage of sulphur in an organic compound 0.15g of which on subjecting to carius method of suphur estimation produced 0.5g of BaSO4

(Ba = 137, S = 32, O = 16) ? 3

22. a) Explain the structure of diborane by drawing a suitable diagram. 2

b) Why SiCl4 gets hydrolysed but CCl4 does not ? 1

23. a) Write a reaction by which BeCl2 can be prepared. 1 b) Why solvay process can not be extended to manfacture K2CO3 ? 1

c) Why salts of Be can not be detected by flame test ? 1

24. a) Why hard water does not give lather with soap ? 1

b) Complete the reaction and balance it 1

clip_image005 Pbs + H2O2

c) How the presence of H-ions be confirmed in Ionic hydrides 1

25. For a reaction , clip_image007H and clip_image007[1]S are 30.56 KJmol-1 and 66JK-1 mol-1 respectively calculate the temperature above which the reaction

would be spontaneous. 3

26. a) Why does the viscosity of a liquid decreases with increase in temp ? 1

B) What is the pressure exerted by 2 mole of a gas enclosed in a 100ml vessel at 270C ? (Given R = 0.0821 lit atm mol-1 K-1) 2

27. a) Why bond angle is NH3 is lower that in CH4 even though the same hybridization is involved in both cases ? 2

b) Why H2O is polar but CO2 is non polar ? 1

28. a) Mention two limitations of Bohr’s Model of atom 2

b) Calculate the wavelength of an electron moving with a kinetic energy of

3x10-25J (mass of electran = 9.8 x 10-31Kg) 3


a) Out at 3d and 4s sub shells which one would have lower

energy and why ? 2

b) What would be the frequency of radiation emitted when an electron moving within a hydrogen atom undergoes transition from fifth to second energy level? 3

29. a) Derive the relationship between kp and kc 3

b) The value of kc for the reaction

2A = B +C is 2 x 10-3. At a given time the composition of reaction mixture is [A] = [B] = [C] = 3 x 10-4 M. In which directions will the reaction proceed? 2


a) Derive the relationship between Ka and α of a weak c molor acid HX. 3

b) Calculate the pH of 0.01 M KOH assuming complete dissociation. 2

30. a) Why wurtz reaction is not considered to be a suitable method for preparing

alkanes with odd no. carbon atoms ?

b) Explain the eclipsed and staggered conformation of ethane by Newman’s projection formula. 1

c) Complete the reaction : 1

CH3 – CH2 – CH = CH2 + HBr à


a) Explain the term β – elimination with an example. 2

b) Draw the Geometrical isomers of but – 2 – ene and explain which one would be polar. 2

c) Complete the reaction :

clip_image008 OH


+ Zn

Monday, March 12, 2012

Class XI Physics Annual Exam Question Paper

Download and practice the Annual Exam question Paper in Physics for Class 11 conducted by KVS Chennai Region.

class xi physics annual exam

The question paper consists of many frequently asked questions

Saturday, March 10, 2012

Plastic Bags and Related issues

Kerala Government has recently issued directives to prevent free supply of plastic carry bags from shops. Is this a good move?

What's happening now?

The shopkeepers have started charging for the plastic bags even without asking the customers. This in turn increases the use of plastic rather than decreasing it. Now the customers have adjusted themselves to spend Re. 1/- to Rs. 5/- instead of carrying a carry bag from home.

If the ultimate aim of these drive is to save our mother earth, there must be a ban Say no to plastic carry bagson plastic and alternative measures must be planned and implemented. Instead of asking the shop keepers to charge for plastic bags, ask them not to keep plastic bags, but sell non-plastic carry bags instead.

It could have been better !

Here are some suggetstions.

  • Let the shop keepers supply paper carry bags or non plastic, biodegradable bags.

  • If the shopkeepers want to sell carry bags, it must be without the BRAND of their shop/business etc and let them provide good quality reusable bags.

Friday, March 9, 2012

Class 10 CBSE Science Summative Assessment II

Download A Model Question paper for Class 10 CBSE Science Summative Assessment II


Click here to Download the Marking Scheme

Thursday, March 8, 2012


Yes. Visit for online help in CBSE Chemistry

Monday, March 5, 2012

How was the CBSE Physics Exam 2012?

How was AISSCE Physics Question Paper 2012?

  • Was the Board question paper 2012 up to the standard?

  • Were there any questions out of syllabus?

  • Was any of the questions too tough?

  • Were there any unexpected questions?

  • How was the numerical problems?

  • Did you get sufficient time to answer the questions?

Please post your response soon. Your responses on AISSCE Physics Question Paper 2012 can affect the marking/ evaluation and eventually the marks. Comment honestly.




Teachers from different cities have already sent their representation on the problems and anomalies found in the question paper. If your teacher hadn't done so, Hurry!!!. Request your teachers to have a thorough analysis of the question papers (All sets) and send the difficulties and anomalies in proper format to CBSE. (There is a format available at schools to send anomalies and problems in CBSE question Paper).
CBSE will consider these representations received while finalizing the marking scheme.

Wish you Good Luck ! Dear students.

Distinguish Plane mirror, Concave mirror and Convex mirror without touching

How will you identify a plane mirror, a concave mirror and a convex mirror without touching their surface?


If you look into a plane mirror, you can find that the size of the image is same as that of the object.

If you look into a concave mirror, you can see an enlarged image when placed close and can see an inverted image when kept away.

A convex mirror always forms a small and erect image.

Sunday, March 4, 2012

Marks Distribution per chapter for CBSE Board Exam 2012

Please find below the chapterwise marks distribution for AISSCE 2012 (CBSE Board Examination 2012)

Unit I Electrostatics - 08
Unit II Current Electricity - 07
Unit III Magnetic effect of current & Magnetism - 08
Unit IV Electromagnetic Induction and Alternating current - 08
Unit V Electromagnetic Waves - 03
Unit VI Optics - 14
Unit VII Dual Nature of Matter - 04
Unit VIII Atoms and Nuclei - 06
Unit IX Electronic Devices - 07
Unit X Communication Systems - 05
Total  - 70

Friday, March 2, 2012

Understanding the concept of Lenz’s law

I have a problem in understanding the concept of Lenz’s law

(Chap: Electromagnetic induction).
Can anyone help me in understanding this concept?

Thank you.

Posted Yugansh Rathor




2008 DELHI

· Which country has the lowest sex ratio in the world? What is its sex ratio?

· Name the country which has the highest human development index


· Name the country where practically every farmer is a member of a cooperative society


· Which stream of migration is dominated by male migration in India?

Rural to urban

· What is the rank of India in human development index among the countries of the world in 2005?

· What is the meaning of human settlement?

· Which are the two main types of iron ore found in India

· What was the main aim behind establishing border road organisation in India

· Name the biggest sea port of India

· What is the main reason of degradation of the quality of water in India

· State six approaches of human geography

· Explain with examples any three geographical factors which influence the distribution of population in the world.

· Explain three characteristics of modern large scale manufacturing in the world

· Compare the features of rural and urban marketing centres of the world in three points