Conditional Probability

IIT JEE 2009 Paper-1 Physics Centre of Mass Problem

Prasanna - An IITM Alumnus

Refer: This article.

While this post may not be related to JEE directly, it may have inspirational value. Prasanna, an IIT Madras alumnus (senior to me) has done us proud. He is the composer of the original music of the Oscar award winning documentary, "Smile Pinky". I have seen him playing at OAT, CLT & SAC (IITM students/alumni must be familiar with these locations) and have sometimes taken inspiration from him to refine my guitar playing. While I am not a connoisseur of Carnatic music, it is my understanding that he has used his guitar playing skills in Carnatic music enormously. The string orchestra of the title track of the Oscar nominated movie, "Lagaan" composed by A. R. Rahman was arranged and conducted by Prasanna. He has also worked with Lakshmikant Pyarelal, Illayaraja*, Hariprasad Chaurasia, Sivamani** to name a few.

Changing his career stream after IITM degree, Prasanna pursued his passion for music and graduated from Berklee College of Music in Boston.

*Illayaraja is a well known film music composer. He has conducted show at IITM OAT during the annual function formerly called Mardi Gras (now called Saarang). In that show, S.P. Balasubrahmanyam & Chitra were also there.
**Sivamani is a well known drummer. He has performed at IITM OAT.

Q & A

A non conducting ring of mass m and radius R has a charge Q uniformly distributed over its circumference. The ring is placed on a rough horizontal surface such that the plane of the ring is parallel to the surface. A vertical magnetic field B=B0t^2 Tesla is switched on. After t second from switching on the magnetic field the ring is just about to rotate about vertical axis through its centre. Find the friction coefficient between the ring and the surface.

Solution (.wmv download)

IIT JEE 2008, Paper I, Maths Section, Error

The detailed solution is provided in .pdf file which is taken from the source file of an eBooklet undergoing editing.

.pdf file

References:

IIT Website Answer
The Telegraph Article