## Saturday, March 21, 2015

### How was class 10 and 12 mathematics question paper cbse

Many commented that mathematics   exam  class 10 and class 12 was difficult. How did you feel?

## Sunday, March 15, 2015

### Chapter wise solutions to H C Verma’s Concepts of Physics Part 1

Problems from H C Verma‘s Concepts of Physics is considered a must work out assignment by most of the IIT aspirants.
Here you can find the solutions to the problems chapterwise. The downloads are based on the old edition of HC Verma’s Concepts of Physics. In case the book is revised, the answers and solutions may not match. Students will have to use your senses to find out. We cannot reproduce the questions for reasons known to all.
If you donot have a copy of HC Verma’s concepts of Physics, Buy it here at the lowest price.

### Rotational Mechanics – HC Verma’s Concepts of Physics – Solution

HC Verma’s Concepts of Physics - Chapter 10 - Question 15
Find the moment of inertia of a uniform square plate of mass m and edge a about one of its diagonals.
The question was posted by Ankit
Solution:
Let the moment of inertia about the axis through the centre of the square plate perpendicular to the plane, assumed to be along Z axis, be I. Now the square plate will be in the XY plane. Let the X axis and Y axis be parallel to the edges and passing through the centre.
Then, we know that Ix = Iy = ma2/12
Then, according to perpendicular axis theorem,

### Solutions to HC Verma’s Concepts of Physics – Weblinks

We found the following website links which offer solutions to HC Verma’s Concepts of Physics.

Though there are some errors and omissions, these links will help at least get ideas which lead towards the solution. Students are advised to try to solve the problems themselves and consult the solution only if they are not getting the correct answer. Please satisfy your own knowledge and understanding before believing on any online solutions.

Please bring to our notice if you find any error in these online solutions.

Weblinks for Solutions to H C Verma’s Concepts of Physics

### Reference Books in Physics Suggested by CBSE for class XI and XII students

1.      Fundamentals of Physics

-         David Halliday, Robert Resnick, Jearl Walker        Asian Books Pvt. Ltd., New Delhi

2.      Facets of Physics :  A conceptual Approach    West Publishing Company

3.      University Physic
-         H.D Young, M.W.Zemansky and F.W.Sears        Narosa Pub. House

4.      Physics – Foundations and Frontiers
-         George Gamow and J.M.Clearland        Tata Mcgraw Hill

### How evolution has shaped our lungs? A physics perspective

In a study published in European Physical Journal E how evolution has shaped our lungs through successive optimizations of physical parameters such as conservation of energy and speed of delivery. Two French Physicists, Bernard Sapoval and Marcel Filoche from École Polytechnique in Palaiseau, France, are involved in the research.
Our system is made from bronchial tree meant to move air flow through the lungs joined with associate alveolar method meant to catch your air. each equally are usually afflicted by diverse form of optimisations. merely tree-like set ups, your paper shows, are ready to effectively nourish parts above a small size, below which sometimes parts are usually alone feasted by merely diffusion. Specially, your authors initial display of which electricity losses regarding liquids through transport are usually minimised within a tree-like composition regarding form dimensions 3. Minute, they show that this optimised tree can be ‘space-filling’ for you to optimise proximity towards the operational alveolae. Finally, they display that your method meant to scale back the time period place in to

## Quick Revision Study Materials for Class XII

 Electrostatics Current Electricity Thermoelectricity Electromagnetics Electromagnetic Induction AC Circuits

## Online practice tests for JEE 2014

Mock Test for Practicing of Computer Based Examination of JEE (Main) 2014   |   Test 1   |   Test 2   |  Test 3   |   Test 4
What are the advantages in opting for Computer Based Examination?
a) The candidate can review or re-answer any question at any point of time during the examination.
b) The candidate can change the option of the answer during the exam duration and it is one of the most important feature of computer based examination
c) The candidate also has the option to mark any answer for review at later stage during the examination.
d) There will be a panel on computer screen showing all the question nos in different colour scheme which will indicate which are the questions answered, left un answered and marked for review
e) Candidate gets the flexibility in choosing the exam date of his/her choice as per his/her convenience.
f) It will make Candidate feel confident on use of Information technology.
g) You can also save upto Rs. 400 in Exam fees compare to Pen/Paper mode.

### Latest Board Sample Papers and Guess Papers

Hi!
Now is the time to buy sample question papers and Guess papers to excel in Board Exams. Just click the link below and you can buy CBSE Sample Papers and Guess papers at lowest price. There a wide range of them and you can select the ones of your choice.

### Semiconductor Devices :: Some Questions for Practice

SEMICONDUCTORS
1. Draw a circuit diagram of OR gate.
2. What is a logic gate?
3. What types of charge-carriers are there in a n-type semi conductor?
4. Give the logical symbol of an AND gate. Mark the inputs and outputs.
5. Draw the logic symbol for a NAND gate.
6. Which biasing will make the resistance of p-n junction high?
7. Write the truth table for OR gate.
8. What is the change in the collector current, in a transistor of a.c. current gain 150, for a 100ÂµA change in its base current?
9. When the voltage drop across a p-n junction diode is increased from 0.65V to 0.70V, the change in the diode current is 5mA. What is the dynamic resistance of the diode?
10. How does conductivity of a semiconductor change with rise in its temperature?
11. Draw a p-n junction with reverse bias.
12. What is the order of energy gap in a semiconductor?
13. Give the ratio of the number of holes and the number of conduction electrons in an intrinsic semiconductor.
14. In the given diagram, is the diode D forward or reversed biased?
15. Convert the number 39 into binary system.

### Revision Questions for AISSE Physics for SA 1

ELECTRICITY
1. Define electric potential difference?
2. Why is an ammeter connected in series in a circuit?
3. Why is a voltmeter connected in parallel in a circuit?
4. State the law that governs the strength of the current passing through a metallic conductor when a p.d is applied across its end. Illustrate this law graphically?
5. State the law which governs the amount of heat produced in a metallic conductor when current is passed through it for a given time. Express this law mathematically?
6. Define resistance. What are the factors on which it depends?
7. A copper wire of resitivity P is stretched to reduce its diameter to half its previous value. What is the new resistivity?
8. Define the S I unit of electric current and potential difference.
9. Derive expressions for equivalent resistance of resistors connected in a. series combination b. parallel.  combination
10. What is an electric fuse? Explain its function.

### Revision Questions for AISSE Physics SA 2

LIGHT - REFLECTION AND REFRACTION
1. What are the differences between real image and virtual image?
2. The radius of curvature of a concave mirror is -46cm.What is its focal length?
3. How will you identify a plane mirror, a concave mirror and a convex mirror without touching their surface?
4. Which mirror has a wider field of view? Why?
5. What happens to a ray of light when it travels from a rarer medium to a denser medium?
6. What will be the signs of u, v and f for a convex lens as per sign convention?
7. State Snell's law of refraction?
8.  A lens always forms a diminished, erect and virtual image .Identify the nature of the lens?
9. Where should an object be placed so that a real and inverted image of the same size is formed using a convex lens?
10. How is the power of a lens related to its focal length?
11. What is the S I unit of power of a lens? Define.

### Clear your concepts - 1 (plus two - electrostatics)

If you are preparing for entrance exams like AIEEE, IIT-JEE, AIIMS, etc. then your concepts should be very very clear. To clarify your concepts keep answering the questions that will appear in this series of clear your concepts.

1. What is the minimum value of permitivity?
2. What is the minimum value of relative permitivity?
3. Does coulomb force between two charges depends upon the presence of other charges in their neighbourhood?
4. Can the charge distribution be really continuous in strictest sense of term?
5. It is difficult to carry out electrostatic experiments on humid days. Why?
6. A negatively charged rod attracts a suspended object. Can we conclude that the object is positively charged?
7. Repulsion is the sure test of electrification. Explain.

### Bad Handwriting? Don't worry ! Here are some tips.

Bad hand writing is a cause of worry for many. They think that it cannot be improved easily. But, you can make your hand writing attractive with a little care and following the three precautions
1. Keep the same size (Take care to write letters of same size)
2. Keep the same level (All letters should come in the same level.)

## Monday, March 9, 2015

### How was the physics question paper?

How was the AISSCE physics question paper 2015? Were there questions outside syllabus. Was it too tough? Respond now to let your voice heard.

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Get free help in physics at www.plustwophysics.com

## Saturday, March 7, 2015

### A Question from Optics

In method of determining refractive index of transparent liquid with help of convex lens and plane mirror ,an equi double convex lens of refractive index 1.5 has been taken….
Sir plzzzz tell what is the relation for refractive index of liquid of convex lens and that of combination