Buffer Action Application & Solubility Product

The embedded version of this class can be seen below. The fullscreen version is available here .

Introduction to Logarithm

The introductory class to logarithm.

Unified Entrance (ISEET/New JEE+Board)

ISEET – as it may possibly be called – may not itself be as controversial as the weightage of normalised board score is in the proposed new engineering entrance policy. This of course is due to the presence of large number of boards with different syllabi, testing & evaluation ecosystem. Contrary to some views that this is being done all of a sudden, a proposal of this kind was not entirely unexpected (refer this). It has been a while that reform process is on to bring in more emphasis on school education in engineering entrance process and things like min. percentage marks in 12^th and limiting number of attempts in JEE have already been implemented in IIT entrance process to achieve this. If board exams can be fairly normalised and they do not merely test the facts & memory, there would not be so much opposition to the proposal. If the new procedure for entrance comes into effect from 2013 for the first time, then some of those who are appearing for the board exam in 2012 and wish to take entrance in 2013 may be at some disadvantage since they might not have concentrated so much on the board exam in 2012. So, for 2013 entrance as a special case, the board marks need not be considered for weightage. Moreover, an exam of ISEET type needs to be conducted several times in a year. From 2014, the exam can be conducted online which can make it easier to be conducted several times in a year. The admitting institutes (like IIT, NIT etc.) that can assign up to 60% weightage to ISEET in their selection process should be allowed to choose the weightage on individual subjects also that are covered in ISEET.

Things will become clearer in future. Yesterday, i.e. on 18^th Feb., JAB meeting was expected whose outcome is not yet known. At this stage it appears that the new entrance procedure could be a reality for at least central institutes from year 2013 if there is no legal hurdle and states can join in times to come. There is a meeting with states on 22^nd Feb. one of whose agenda is to discuss this matter (the agenda is available  here) . On a side note, it is amusing to see that while it is mentioned in the agenda that the test would be of 3 hour duration, the time is given as 10 to 12 for ISEET-Main (see below).

Open Organ Pipe Reflection Q & A

Question: In closed organ pipe, the sound gets reflected from the rigid boundary. This makes sense. But, in open organ pipe there is no boundary at the end. So, how can sound reflect?

Answer: One is accustomed to seeing objects getting bounced from rigid wall and not from empty space. Hence, this may look odd if something is said to be reflected from the open end. Sound is not an object but is disturbance. The sound wave is reflected whenever medium changes or there is discontinuity in the medium. In open organ pipe when the sound reaches the open end, there is a change from a narrow region to a vast region. Because of this discontinuity in the medium, reflection takes place.