Problem solving tricks-Right hand rules (Magnetic fields due to currents)

Right hand rule for cross product:-
Consider that c is the cross product of two vectors a and b i.e.,
c=a x b
If direction of vector a is along the x axis and that of b along z axis then direction of vector c could be find using right hand rule for cross products. With the thumb, index, and middle fingers at right angles to each other the first (index) finger can represent a, the first vector in the product; the second (middle) finger, b, the second vector; and the thumb, c, the product. So direction of vector c is perpendicular to the plane containing vectors a and b. This rule can be used in determining the directions of torque and angular momentum vectors and also to find the direction of the force on current carrying wire in an magnetic field.


Right hand thumb rule:-
This rule is used in situations when rotation is specified by a vector and we need to relate a curled element and a straight element , many such situations arises when you study magnetism. This can be done when you curl your fingers and straighten the thumb of your right hand. As an example you can consider an electric current passes through a straight wire. Here, the thumb points in the direction of the conventional current (from positive to negative), and the fingers point in the direction of the magnetic lines of flux.

Tips for success

1. Find your own deep and compelling reason to successfully learn your subject and pass your exams.

2. Plan your time to include study, revision and social commitments - a balance of having fun, taking breaks and studying is vital.

3. Use multi-coloured Mind Maps® for your notes.

4. Review your notes regularly to reinforce your new-found knowledge.

5. Swiftly skim through your text books and course material before you read them in depth to give you an overview of your subject.

6. Learn how to remember lists of things by linking each item to a location on a journey or route you are familiar with around your town. You could even use your own home.

7. Before you do any revision, warm up by doing some gentle exercise to relieve any tension in your body and to get a rush of healthy oxygen flowing to your brain.

8. Do past papers under thorough exam conditions as often as possible to familiarise yourself with the format and the pressures of working under exam conditions.

9. In an exam, make sure you read the question completely and fully understand what the examiner wants before you allocate your time and begin answering the questions.

10. If you are faced with a mental block breathe deeply, relax and ask yourself "If I did know the answer to this question, what would it be?"

-memory expert
MICHEL TIPPER...................!!!!!!!!!!!http://www.michaeltipper.com/

How to master Physics

If you are a student then before attending your class do preparations for your lecture which means go through your text book , read the chapter and prepare for your forthcoming lecture.

Try never to miss your lectures and listen them carefully

Since you have read your lessen before you can easily clear your doubts and have discussion with your faculty.

Never forget to take your notes during your lecture.

After going home prepare a fresh copy of your notes and short notes of your lessen so that you can revise them easily while studying for your exams. Yes never forget to jot down your doubts and their possible explainations.

After compleating your chapter do not forget to practice related problems as they help you to clear your concepts. The more problems you solve the more comfortable you get with the subject.

Revise your lessen regularly so that it becomes impossible for you to forget the chapter.

IITJEE 2011 tips and tricks

1. If yo are trying to attempt for IITJEE just after your board exams then try not to pick up the new topic which you haven’t studied yet.


2. If your main aim is IIT JEE then you should try to read the basics for the chapters you have already prepared, as their wouldn’t be even a single question which you would find in the books,it’s the basics that help while solving the examination.

3. Try to go through the compendiums once, they may come in handy while solving the examination.

4. IIT JEE is not like a war against time,their is plenty of time if you solve the paper systematically.

5. Never try to go for all the questions,if you are sure of 60% paper then it’s pretty enough to get a good rank in IIT JEE,coz for the year 2010 the cut off was around 185...

6. Their is surely going to be lot of questions from cyclic compounds in chemistry so be sure to do them thoroughly,chemistry is the most scoring part in the paper

7. Try to give about 45 minutes to chemistry,55 minutes to physics and the rest to mathematics and also spare 5 minutes in the end to recheck.

8. Don’t stick to one question if you think that the question of 3 marks would take more then 5 minutes then leave it and try at the end ,also if you are not able to solve the question move to the next one,not waste much time on single question.

9. Try to mark the answers simultaneously when you are solving the paper,though many students do mark the answers in the end so plan your time accordingly.









source : iitjeeclub.com

How to simplify circuits with resistors

1. In any given circuit first of all recognize the resistances connected in series then by summing the individual resistances draw a new, simplified circuit diagram.

For series combination of resistances equivalent resistance is given by the equation
R_eq= R₁ + R₂+R₃
The current in each resistor is the same when connected in parallel combination.

2. Then recognize the resistances connected in parallel and find the equivalent resistances of parallel combinations by summing the reciprocals of the resistances and then taking the reciprocal of the result. Draw the new, simplified circuit diagram.
(1/R)=(1/R₁)+(1/R₂)+(1/R₂)

Remember that for resistors connected in parallel combination ‘The potential difference across each resistor is the same’.

3. Repeat the first two steps as required, until no further combinations can be made using resistances. If there is only a single battery in the circuit, this will usually result in a single equivalent resistor in series with the battery.

4. Use Ohm’s Law, V= IR, to determine the current in the equivalent resistor. Then work backwards through the diagrams, applying the useful facts listed in step 1 or step 2 to find the currents in the other resistors. (In more complex circuits, Kirchhoff’s rules can be applied).

Prepare yourself for Competetive Exams

This time is mid of the november and can prove deciding time for those preparing for competetive examinations like IITJEE/PMT/AIEEE etc and various other examinations. Ideally you should nearly complete all your syllabus by this month and if you have not completed it then try to cover the syllabus quickly by the end of this month. After you have completed all your syllabus then start revising it keeping yourself cool and calm.
Try an explore all the topics of your syllabus for the competetive exams. After having looked up and revised complete syllabus you should start practicing simulated exame type situations to increase your confidence there are various websites online where you can take such tests.
So all the best for the preparations of your competetive exams. Stop panicing if you have little time left and large portions to cover just fix your goals and start preparing.

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
link

String, pully and spring

A lot of problems in mechanics involves string, pulley and springs for example masses are attached to string or spring and so on. Here are some concepts you need to remember while solving problems involving string, spring and pulleys.
(1) String
A. If not staded in the question consider the string to be inextensible.
B. Different blocks connected to an inextensible string would have same acceleration and for extensible string blocks would have different acceleration until the string can stretch.
C. Unless otherwise specified consider the string to be light i.e., consider its mass to be negligible in comparison to the block connected to it.
D. For a massless string tension in the string is zero although an ideal massless string is an practical impossibility.
E. Tension on different parts of the string would be different if string possess a considerable mass.

(2) Pulley
A. Unless or otherwise specified consider the pulley to be light having no effect on the system due to its weight.
B. The tension on strion on either side of pulley is taken to be same
C. If not specified consider the oulley to be frictionless in nature.

(3) Spring
A. Unless or otherwise specified consider the spring to be light and force constant of spring is same throughout whole length of the spring.
B. Spring has a elastic property that it can be compressed and stretched easily.
C. To stretch or compress a spring equal and opposite forces have to be applied at both the ends of the spring and in responce spring apply equal and opposite restoring force to bring the spring back to its natural position.
D For small compression and elongations this restoring force is given by Hook's Law which is
F=kx
where k is the spring constant and x is elongation or compression from the natural length of the spring.

So keep solving more and more physics problems Keeping these facts in mind. All the very best for your exams.

IITJEE Tips and Tricks

Solve Force and motion problems easily
(1) First read the problem carefully.
(2) Determine which type of force is exerted in the system and where it is exertwd.
(3) See whether Newton's law of motion are applicable for the particular system or not i.e., see wherher frame of referance you are working with is inertial or non-inertial frame of refrence.
(4) Determine the system of units you have to use to solve a problem. If physical quantities in the question are given in different units then convert them to a convinent unit you want to work with generally S.I. system of unit is used in our text books.
(5) See if frictional forces are acting on the system if yes then take them into account.
(6) While taking care of friction forces see if they are static or kinetic in nature and accordingly work with them.
(6) Look for the direction of the frictional forces.
So keeping these simple points in mind you can solve force and motion problems easily

How to prepare for Physics for IITJEE

IITJEE is one of the toughest examination in India.SO it requires lots of systematic efforts to pass the examination.
Here i would to try to explain what should be the strategy and plan for physics for IITJEE

• First things is the right selection of books for the IITJEE as good books play an important role in clearing the concept in Physics.
  You can check at the following links for the list of books for the IITJEE.
  
  IITJEE Physics Books
  
  
  
• Second things is to plan your syllabus .Decide about the time for the each units.I will be soon giving u the IITJEE physics planner for theb whole year which will greatly help you in planning.
  
• The next steps to stick to the schedule and start the study.First of all clear your all concepts.Read the chapter many times so that concept becomes crystal clear and you can connect the concept with our daily life.For example.Lets take Projectile Motion.A baseball in motion describes an Projectile motion.You can think of baseball example in learning the concepts.It will be good if you can prepare some notes of the chapter for fast revision.
  Check out your concept by attempting the conceptual questions.You can lots of comceptual test on the my blog.
  
  You can get good study Material at the following link
  IITJEE Study Material
  
  
• Once you have cleared the concept,you are ready take the questions.First study some examples to get the feel of the concept.While going through examples,you can see and analyze the way a particulr physical concept is applied towards solving the problem. This will help you a great deal while you begin to solve problems.Try to find the best possible way to tackle the problem.Lets take the example for Projectile motion
  
  1.Gather all the information from the question
  2.Select a coordinate system and resolve the initial velocity vector into x and y components.
  3.Follow the techniques for solving constant-velocity problems to analyze the horizontal motion. Follow the techniques for solving constant-acceleration
  problems to analyze the vertical motion. The x and y motions share the same time of flight t.
  
  You can find lots of such ways and hint from the following link
  IITJEE Tips
  
• Revise your material and practice questions on a systematic basis.
  
• Attempts the question in previous year IITJEE questions papers.This will give you a feel of the IITJEE questions.You can find the papars and solutions in the below link
  IITJEE Previous Year Papers
  
  
• Take Test on regular basis.It give you the feel of the examination.Give you full attempt to the test.Take online Test on the below links.
  IITJEE Test Series
  
• Take some simulated IITJEE test series (not online) by the some renowned institues.This will help you in preparing for the Main Examination

Best of luck
Physics Expert