Wednesday, October 21, 2009

All India Pre-Medical / Pre-Dental Entrance Examination -2010 (AIPMT 2010)

Central Board of Secondary Education (CBSE), Delhi has invited applications in the prescribed form for All India Pre-Medical / Pre-Dental Entrance Examination -2010 as per the following schedule for admission to 15% of the merit positions for the Medical/Dental Courses of India

1. Preliminary Examination – 3rd April, 2010 (Saturday) 10 AM to 1 PM

2. Final Examination – 16th May, 2010 (Sunday) 10 AM to 1 PM

The Preliminary Examination will consist of one paper containing 200 objective type questions (four options with one correct answer) from Physics, Chemistry and Biology.

The Final Examination is only for those who qualify in the Preliminary Examination. It will consist of one paper containing 120 objective type questions (four options with one correct answer) from Physics, Chemistry and Biology.

Candidate can apply for the All India Pre-Medical/Pre-Dental Entrance Examination either offline or online as explained below:

Offline (On prescribed application form)

Offline submission of Application Form may be made using the prescribed application form. The Information Bulletin and Application Form costing Rs.800 for General & OBC Category Candidates and Rs.450/- for SC/ST Category Candidates can be obtained against cash payment from any of the specified branches of Canara Bank/ Regional Offices of the CBSE. Find details at


Online submission of application may be made by accessing the Board’s website Candidates are required to take a print of the Online Application after successful submission of data. The print out of the computer generated application, complete in all respect as applicable for Offline submission should be sent to the Deputy Secretary (AIPMT Unit), CBSE, Shiksha Kendra, 2, Community Centre, Preet Vihar, Delhi-110 301 by Speed Post/Registered Post in such a way that it should reach the Board on or before the last date. Fee of Rs.800/- for General and OBC Category Candidates and Rs.450/- for SC/ST category candidates may be remitted in the following ways :

1. By credit card, or

2. Through Demand Draft in favour of the Secretary, CBSE, Delhi drawn on any Nationalized Bank payable at Delhi.

Instructions for Online submission of Application Form are available on the website

The last date of receipt of Application Form for both offline and online is 04.12.2009.

In case the application is submitted online, printout of the computer generated form complete in all respects as applicable for offline submission must reach The Deputy Secretary (AIPMT Unit), CBSE, Shiksha Kendra, 2, Community Centre, Preet Vihar, Delhi-110301 on or before the last date. A grace period of 15 days will be allowed from the last date of submission of the application to the candidates belonging to remote areas viz. Mizoram, Assam, Meghalaya, Arunachal Pradesh, Manipur, Nagaland, Tripura, Sikkim, Lahaul and Spiti Districts and Pangi sub-division of Chamba District of Himachal Pradesh, Andaman & Nicobar Islands and Lakshadweep.

Visit the web site for all details and information updates.

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You will find some old AIPMT questions with solution on this site. You can access these questions by searching for ‘AIPMT’, making use of the search box provided on the site.

Saturday, October 17, 2009

EAMCET (Engineering) 2009 Questions on Photoelectric Effect

Questions on photoelectric effect are usually interesting. One or two questions in this section often find place in entrance examination question papers. I give below two questions on photoelectric effect which were included in the EAMCET (Engineering) 2009 question paper:

(1) The work function of a certain metal is 3.31×10–19 J. Then the maximum kinetic energy of photo electrons emitted by incident photons of wave length 5000 Ǻ is (given h = 6.62×10–34 Js, c = 3×108 ms–1, e = 1.6×10–19 coulomb)

(1) 2.48 eV

(2) 0.41 eV

(3) 2.07 eV

(4) 0.82 eV

It will be useful (as I have mentioned on earlier occasions) to remember that a photon of wave length 1000 Ǻ has energy of 12.4 eV. In other words, the product of the wavelength in Angstrom (Ǻ) and the energy in electron volt (eV) of any photon is 12400 units. Therefore, the energy of 5000 Ǻ photon is 12400/5000 = 2.48 eV.

[You can calculate the energy (E) of the photon in joule using the equation, E = hc/λ and then convert it into electron volt by dividing it by 1.6×10–19 as 1 eV = 1.6×10–19 joule. But you will have to spend too much of your valuable time for this].

The work function of the metal is 3.31×10–19 J = (3.31×10–19)/(1.6×10–19) eV = 2.07 eV nearly.

The maximum kinetic energy of photoelectrons emitted = Energy of incident photon – Work function = 2.48 eV – 2.07 eV = 0.41 eV.

(2) A photon of energy ‘E’ejects a photo electron from a metal surface whose work function is W0. If this electron enters into a magnetic field of induction ‘B’ in a direction perpendicular to the field and describes a circular path of radius ‘r’, then the radius ‘r’ is given by (in the usual notation)

(1) √[2m(E W0)/eB]

(2) √[2m(E W0) eB]

(3) (1/mB)√[2e(E W0)]

(4) (1/eB)√[2m(E W0)]

The kinetic energy (k) of the photo electron is given by

k = E W0

The momentum p of the photo electron is related to its kinetic energy as

k = p2/2m,

Therefore, momentum p =√(2mk) = √[2m(E W0)]

The radius ‘r of the circular path followed by the electron in the magnetic field is given by

r = mv/qB

[This is obtained by equating the magnetic force to the centripetal force:

qvB = mv2/r]

Since mv = p, we have r = p/qB = p/eB = (1/eB)√[2m(E W0)].

You can access all posts related to photoelectric effect on this blog by clicking on the label ‘photoelectric effect’ below this post.

You will find more questions (with solution) at AP Physics Resources.

Friday, October 09, 2009

AIPMT 2009 Multiple Choice Questions on Work, Energy & Power

How strange is the lot of we mortals! Each of us is here for a brief sojourn; for what purpose we know not, though sometimes sense it. But we know from daily life that we exist for other people first of all for whose smiles and well-being our own happiness depends.

–Albert Einstein

Three questions from the section ‘work, energy & power’ were included in the AIPMT 2009 question paper. Here are those questions with solution:

(1) A block of mass M is attached to the lower end of a vertical spring. The spring is hung from the ceiling and has force constant value k. The mass is released from rest with the spring initially unstretched. The maximum extension produced in the length of the spring will be:

(1) 2 Mg/k

(2) 4 Mg/k

(3) Mg/2k

(4) Mg/k

If x is the maximum extension produced, we have

Mgx = ½ kx2, on equating the decrease in the gravitational potential energy of the mass M to the increase in the elastic potential energy of the spring.

Therefore, x = 2Mg/k

(2) A body of mass 1 kg is thrown upwards with a velocity 20 m/s. It momentarily comes to rest after attaining a height of 18 m. How much energy is lost due to air friction? (g = 10 ms–2)

(1) 30 J

(2) 40 J

(3) 10 J

(4) 20 J

The initial kinetic energy of the 1 kg mass is given by

½ mv2 = ½ ×1×202 = 200 J.

The gravitational potential energy of the 1 kg mass at its maximum height is given by

Mgh = 1×10×18 = 180 J.

The energy lost due to air friction is therefore equal to 200 – 180 = 20 J.

(3) An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

(1) mv2

(2) ½ mv2

(3) ½ m2v2

(4) ½ mv3

Mas of water flowing out per second through the hose is mv. Therefore, kinetic energy imparted per second to the water is ½ ×(mv)×v2 = ½ mv3 [Option (3)].

You will find useful posts in this section here.