2014 JEE Advanced|Physics|Capacitors 2014 ஐ ஐ டி ஜே ஈ ஈ Advanced இயற்பிய...

UNIT 3 -- Problem 1, A BAR MAGNET HAVING A MAGNETIC MOMENT pm IS CUT INTO TWO PIECES ALONG THE AXIS ...

A bar magnet having a magnetic moment p­_m is cut into four pieces i.e., first cut into two pieces along the axis of the magnet and each piece is further cut along the axis into two pieces. Compute the magnetic moment of each piece.
Solution தீர்வு

SOLUTION FOR IRODOV PROBLEM 4.34 -- two masses interconnected by a spring -- one body performs free vertical harmonic oscillations -- maximim and minimum force

I have slightly altered the problem so that it is general in its composition; I must admit that, in spite of looking up to the answer, I had nearly spent half-a-day in understanding the solution completely. Now here is the problem:
A body A of mass m₁ and a body B of mass m₂ are interconnected by a spring as shown in Fig. 2. The body A performs free vertical harmonic oscillations with amplitude A and angular frequency ω. Neglecting the mass of the spring, find the maximum and minimum values of force that this system exerts on the bearing surface.  
Solution: 

 

 

MODEL QP 11 PHYSICS

Hi,
Here is the Model QP for 11th Physics (full portion).
DL link : 11 PHYSICS MODEL QP

STUDY MAT FOR FLOOD AFFECTED 2016

Hi,
Here is the AMMA BOOK (12th Phy) for the flood affected released in 2016. CLICK
Also here is the official SCERT link for all other subjects. <http://www.tnscert.org/cmrelmat.html>
ALL THE VERY BEST

RIGHT HAND PALM RULE

Hi,
Here is how to use the RIGHT HAND PALM RULE, வலது கை உள்ளங்கை விதி.
YOUTUBE VID

LENZ LAW APPLICATION

Hi All,

Here is a well-known teaser in Lenz law. Find the direction of the induced current in both the cases.
Situation: A coil is in the horizontal plane. A bar magnet is falling down through it. (1) What is the direction of induced current as the magnet passes with N pole facing down? (2) What is the direction of induced current as the magnet passes with S pole facing up?

(1) CLICK HERE FOR (1)
(2) CLICK HERE FOR (2)

Answers will be in the next blog

XII PHYSICS VOL 1-6

Hi!
Here is a Vol. 1-6 Physics QP (for TN State XII). D/L it and write a test. Scan it and send it to
<phy14resonance@gmail.com>
CLICK HERE

2016 TN BOARD PHYSICS MCQ ANSWER KEY

Hi,
Here is a tentative answer key for 2016 TN State Board Physics MCQs.
If you have any difference of opinion pl comment.
CLICK HERE

MCQs TEST

Hi,
Take this MCQs test. Sure it will help you sharpen your knowledge.
MCQs TEST FOR PLUS TWO PHYSICS
Prepare well. Do well. ALL THE VERY BEST
 Answers.                                    
CLICK HERE 
For Solution Hints CLICK HERE 

PHYSICS OFFICIAL SCORE KEYS

Here are some of the Tamil Nadu Board Exam Official Score Keys for PHYSICS. More to follow...

MARCH 2006 PHYSICS SCORE KEY
MARCH 2007 PHYSICS SCORE KEY
MARCH 2008 PHYSICS SCORE KEY
MARCH 2009 PHYSICS SCORE KEY
MARCH 2011 PHYSICS SCORE KEY
MARCH 2012 PHYSICS SCORE KEY
MARCH 2013 PHYSICS SCORE KEY
MARCH 2014 PHYSICS SCORE KEY
MARCH 2015 PHYSICS SCORE KEY
MARCH 2016 PHYSICS SCORE KEY

Pl Note: These keys are only for reference. Score keys are not universal and constant i.e., every new score key may have different value points allotted for the same question. You may have to apply your judgment and present accordingly.

ANOTHER TEASER FROM HALF YEARLY PAPER

Qn. When the current sensitivity of a galvanometer increases, the voltage sensitivity
       (a)  increases     (b)  decreases     (c)  may or may not increase      (d)  does not change
My take:  (c) may or may not increase
Explanation:

Consider four cases: (i) N - no. of turns, (ii) B - magnetic induction through the coil, (iii) A - area of the coil (not cross-sectional area) and (iv)  c - couple per unit twist

Now,
C.S. = θ/I = NBA/c ==>

C.S can be increased by increasing (i) N, (ii) B or/and (iii) A. Also by (iv) decreasing or having low c value. Qn. does not say how C.S has been increased. 

It might be due to increase in B, say. 

In that case [as also in cases (iii) and (iv)], C.S. obviously will increase and so too will V.S.  [since V.S. = θ/V = θ/IG]. But when C.S is increased by increasing N, V.S. will not increase.

==> When C.S. increases, V.S. may increase [case (ii), (iii) and (iv)] or may not increase [case (i)].

Pl give your opinion.

TEASER IN PHYSICS

A hollow metal sphere A of radius 6 cm is uniformly charged with 10 μC. Another hollow metal sphere B of radius 3 cm is uniformly charged with 6 μC. A and B are connected externally by a wire. What happens now? Will the charge flow?

 Ans.  
Charge flows from A to B. 
Explanation.  
A hollow metal sphere with uniform charge acts as if the entire charge were concentrated at its centre; and since the electric field inside is zero, the potential is the same from surface to its centre. 
==> V = k*q/r (V-potential, q-charge, r-radius)
VA = k*10/6 & VB = k*6/3 ==> VA < VB
Now, when the two spheres are connected by a wire, charges flow until their potentials become equal; charges that flow through the wire are the free electrons and they will travel from lower to higher potential i.e., from sphere A to B.
Note: However, conventional current flows from B to A.    

HALF YEARLY 2016 PLUS TWO PHYSICS SCORE KEY

Hi!
Here is the Score Key for 2016 Half-yearly Physics. If you have any difference of opinion, pl comment.
CLICK HERE
Note: Bear with the typo -- Q.No. 6 -- May or may not increase

HALF YEARLY 2016 PHYSICS MCQ ANSWER KEY

Dear All,
Here is the answer key for TN HALF-YEARLY EXAM 2016 - PHYSICS (Q.No. 18 ans. corrected)
Pl feel free to give feedback in case of difference.
CLICK HERE
Note: Bear with the typo -- Q.No.6 - c) May or may not increase

REVALUATION REVIEW

DGE has announced that one can download scan copy of the answer script for those who have applied for revaluation from today (28.05.15 - Thu).
* SCAN DOWNLOAD LINK : scan.tndge.in
* REVALUATION/RETOTALLING FORM : CLICK HERE
* LAST DT FOR APPLYING: JUNE 1, 2015 
* for all other important details visit: alleducationnewsonline
* FOR A REVIEW OF PHYSICS (only Phy) PAPER, you may send your d/led copy to:
<ravisankar13.srs@gmail.com>. Opinion will be sent to you through email the same night. You are requested to consult another teacher for second opinion before deciding on.
* TN STATE BOARD +2 PHYSICS MARCH 15 SCORE KEY CLICK HERE

OFFICIAL KEY MAR 2015 PHYSICS TN STATE BOARD XII PHYSICS

Hi All !

Here is the Official Score Key for this Mar 2015 PHYSICS (TamilNadu State Board Exam)  CLICK HERE

இயற்பியல் வினாத்தாளில் சிக்கலான, தெளிவற்ற கேள்விகளால் முழு மதிப்பெண் பெறுவதில் சிக்கல்

இயற்பியல் வினாத்தாள் கடினம் - செண்டம் குறைய வாய்ப்பு
நேற்று (27.03.15) நடைபெற்ற இயற்பியல் தேர்வில் பத்து, ஐந்து மற்றும் மூன்று மதிப்பெண் வினாக்கள் எளிதாக இருந்தன; மேலும் பார்க்க

MARCH 2015 PHYSICS TN STATE BOARD - ONE MARKS - SCORE KEY AND COMMENTS

Dear All!

Here is my ANSWER KEY (TENTATIVE)
 MARCH2015 PHYSICS ONE MARKS SCORE KEY TENTATIVE 

My first reactions to the MARCH 2015 PHYSICS QP of Tamil Nadu State Board Exam:

• Easy q.p as far as Parts II, III and IV are concerned. This is imp. because majority of the students (those who'd want a decent score but may not be centum) could easily do this paper.
• A few MCQs are iffy (i.e., ambiguous and without clarity)    

               for example : Q. No. 14 and 23 in B series

      Q. No. 14 - "A light of wavelength 4000 Å after travelling a distance of 2 µm produces a phase change of " ... so goes the question.

     How can a wave (which is travelling in , god knows, whichever medium) produce a phase change (or if the Question Setter wanted to know the phase change it undergoes?)

• Q. No. 23 - "The direction of the electric field in Millikan's oil drop experiment acts:" ... so the question goes.

   In the original Millikan's patent itself, he uses a COMMUTATOR for reversing the direction of the electric field now and then. How then can one be certain of the direction of the field?

Anyhow, with due regard to their experience and expertise, I feel that our Question Setters need to consider the accuracy/clarity while framing a question.

Some questions are very clearly framed and test the student's understanding of the concept , for eg., Q.No. 26 and 30 in B series. Q. No. 30 especially is very good - the same type of question (Joule's experiment based) was earlier asked in a September 2012 but with a conceptual error. But this time it was spot on. Hats off to you, Question Setters.
       

PHYSICS PRACTICALS VIDEOS

Dear Student!
Here is the link for video help for Tamilnadu State XII Physics Practicals. XII-PHYSICS-PRACTICALS-VIDEOS