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hi all
Whether you are preparing for competetive exams like IITJEE/PMT/AIEEE or you are looking for some serious knowledge in physics you need to check your knowledge time to time so that you are aware of the preperation you have done . So here I am giving you the links for IITJEE/AIEEE test series in physics.Those who are not preparing for such exams can also take the test to check their knowledge. Hope they help you. So take a test of your knowledge in physics
Test series 1
Test series 2
Test series 3
Test series 4
There are three other test series available on general topics in physics for those you would have to register yourself to the
website

for further information contact mailmephysics12@rediffmail.com.

### Static Friction

Physics Study material for IITJEE/AIEEE/PMT In this post we tried to explain static friction which is a important concept to lern while preparing for IITJEE/AIEEE/PMT and other competetive exams. I have also given the link from where you can study the whole chapter.

-We know that frictional forces can also act between the bodies in contact with each other even if they are not moving and such type frictional force is known as static friction

-Consider a heavy metal block kept on the floor and you are trying very hard to push it to another location and you are not able to slide it even by a centimeter

-Since the block is at rest resultant force on it should be zero.To counter balance the force applied by you ,floor exerts a frictional force on the block

-Now if you begin to increase the magnitude of force gradually then bloack does not start moving until force applied is greater then a minimum value of force

-This force of static friction must be overcome by the applied force before the body at rest begin to move

-Force of friction is always equal and opposite to the external applied force as long as the body is at rest

-This means that static friction force is a self adjusting force.It adjust its value accordingly with the increase in magnitude of applied force

-This frictional force cannot be unlimited and its value cannot go beyond a maximum value fms

-This maximum value of static friction between the two surfaces in contact is known as limiting friction
-Thus magnitude of static friction can not go beyond the magnitude of the limiting friction i.e, fs <= fms
-This limiting friction is proportional to the normal contact force (N) between the bodies i.e,
fms= is proportional to N
fmssN
Where N =Normal contact force
μs is the proportionality constant known as coefficent of static friction

-Value of coefficent of static friction depends on the material and roughness of the surfaces of bodies in contact

-fms is the maximum value that force of static friction acting between two bodies can reach

-The actual force of static friction can be equal to zero or less then fms and its value depends on the force applied on the body thus
fs <= fmssN
For full notes on friction visit the link given below

### IITJEE/AIEEE/PMT tips and tricke in electrostatics

1. The force with which two charges interact is not changed by the presence of the other charges.

2. Net force on any charge F=F1+F2+F3+F4+.....

3. Electric field lines extend away from the positive charge and towards thge negative charges.

4. Electric field produces the force so if a charge q is placed in the electric field E the force experience by the charge is F=qE

5. Principle of superposition also applies to electric field

so E=E1+E2+E3+E4+......

6. E is the electric field present due to all charges in the system not just the charge inside in the Gauss law.

7. Flux crossing a closed surface does not depend on the shapes and size of gaussian surface.

8. ∫E.dl over closed path is zero.

9. Electric Potential is scalar quantity.

10. Potential at point due to system of charges will be obtained by the summation of potential of each charge at that point V=V1+V2+V3+V4+..........

For more such tips and tricks click the link given below

### 5 Secrets to Cracking Competitive Exams

They’re not the kind of exams you’re used to in school, but you know you have to prepare hard for them if you want to go to college. Almost every admission procedure requires that you score a certain percentage in one or more competitive exams, so unless you’re good and ready in the most efficient way possible, it’s hard to get your foot in the door that almost every other high school graduate is trying to open. If you’re looking for extra help, here are a few secrets that will help you achieve success:
Start early: Know what you want to do before you graduate from high school and work on achieving your goal step by step. Be familiar with the requirements you must meet, the subjects you need to study, and the grades you must secure. When you begin early, you gain a head start not just on your peers, but also in your attempt to crack the exam.
Do your research: Make a list of the colleges you want to attend and the prerequisites for admission to each of them. Don’t rely on secondhand sources for your information; instead, call the admissions office or check the official website of the institutions you’re interested in and get your queries and doubts resolved. Ask if there are any additional qualifications that you could meet in order to secure scholarships or other perks, and ensure that you send in your application well before the due date.
• Do a little everyday: Studying for an exam is a continuous process, one that must be done little by little and on a regular basis. If you try to cram everything a few days or even a few weeks before the big day, your lack of preparation is going to show you up. When it comes to competitive exams, it’s not just your grades that matter, but how well you’ve done in comparison to every other person who has taken the exam as well. And when a whole nation is competing with you, preparation is everything. So besides starting as early as you can, dedicate a few hours every day to preparing for your exam.
• Time yourself: Most competitive exams are all about time; they’re multiple choice options that have to be solved in less than a minute, and you often have just a few seconds to come up with each answer. While it’s easy to stay within the time limit for standard questions in English and other general subjects, it’s a different issue for those that involve solving mathematical or scientific equations and problems. Sometimes you get so caught up in trying to crack one equation that you neglect too many other questions in the process. So conduct as many dry runs as you can and perfect a way to answer as many questions as you can in the limited time available. Many students perform badly not because they don’t know the answers but because they do not complete the tests for lack of time.
• Stay calm and collected: Don’t panic at any stage of the exam, when preparing for it or writing it. If you’ve prepared well, your confidence should help you stay calm and collected, even when you think you’re pressed for time and the pressure starts to build. When you stick to your game plan, it’s easy to do your best.
By-line:

### Physics questions for IITJEE, AIEEE, PMT preperation

Given below are the questions you can prepare for IITJEE-2011, AIEEE-2011 and PMT-2011 examinations. Few questions from the questions given below have been aske in previous year IITJEE, AIEEE and other such exams.

Question 1. Three capacitors of 8μF , 12μF and 24μF are connected (A) in series combination and then (B) in parallel combination . The ratio of equivalent capacitance in case (B) to that of case (A) is
(a) 11:1
(b) 1:11
(c) 1:1
(d) 3:1

Question 2. A piece of copper and a piece of germanium are cooled from the room temperature down to 80K
(a) resistance of each of them increases
(b) resistance of each of them decreases
(c) resistance of copper increases and that of germanium drcresaes.
(d) resistance of copper decreases and that of germanium increases.

Question 3. A current flows along the length of infinitely -long straight , thin walled pipe then,
(a) magnetic field at all points inside the pipe is same , but non zero
(b) the magnetic field at any point inside the pipe is zero.
(c) magnetic field is zero only on the axis of the pipe
(d) magnetic field is different at different points inside the pipe

Question 4. The line on the earth's surface joining the points where the field is horizontal is called
(a) magnetic maredian
(b) magnetic axis
(c) isogonic line
(d) magnetic equator

Question 5. The principle used in the transmission of signal through an optical fibre is
(a) total internal reflection
(b) reflection
(c) refraction
(d) dispersion

Question 6. Milikan's oil drop experiment established that
(a) electric charge depends on velocity
(b) electron has wave nature
(c) electron has particle nature
(d) electronic charge is quantized

Question 7. For steady direct current to flow in a circuit
(a) circuit must contain a source of emf
(b) charge distribution in circuit must remain unchanged
(c) lines of current density vector are closed one
(d) all of the above

I hope that these question answes will help you prepare physics for IITJEE, AIEEE and PMT exams