Community Physics Problems

  • New visitors are encouraged to start reading topics of interest in the articles forum as the articles can help you digest a lot of information in a short amount of time.
  • Everybody is encouraged to write articles that can benefit prospective and current physics graduate students.

Post Reply
Posts: 7
Joined: Fri Feb 22, 2008 4:00 pm

Community Physics Problems

Post by problems » Tue Feb 19, 2008 1:47 pm

Important Note: New additions to the CPP experiment have been put on hold. Students have been too busy to contribute physics problems and so I have diverted my efforts to improving other aspects of this site.

However, we still have 15 quality Physics GRE style problems to show for the effort. They should be nice practice.

>> cpp1-4.pdf - (last updated 12/05/03)

Note: Please submit any errors found within the Community Physics Problem database.

Note: Also, there were a few problem that were submitted that I thought were perhaps too difficult for the Physics GRE so I thought it was a good idea to include them separately so that some students would not be inclined to spend a disproportionate amount of their time struggling with them. You can find these problems at cpp1-1-challenge.pdf (last updated 12/05/03 - 2 problems)

Note: The original goal was to build a large collection of Physics GRE style problems that could help students prepare for the Physics GRE. In theory, if hundreds of physics students each dreamed up, wrote up, and submitted at least one quality Physics GRE style problem then all of us will have gotton to practice with hundreds of quality physics problems. There you go, a valuable lesson in difference between theory and experiment.

Please contact the webmaster with any questions, comments or ideas.

Posts: 98
Joined: Thu Jun 24, 2010 12:17 am

Re: Community Physics Problems

Post by delsub » Sat Sep 11, 2010 1:37 am

Thanks very much but where are the problem sets 1-3??

Posts: 3
Joined: Fri Aug 02, 2013 1:25 am

Re: Community Physics Problems

Post by superderec » Fri Aug 02, 2013 1:43 am

Hi guys. I just joined in this forum and I have found some great GRE phys type questions that I would like to discuss with you.

for example :

1. A sample of radioactive nuclei of a certain element can decay only by gamma-emission and beta-emission. If the half-life for gamma-emission is 24 minutes and that for beta-emission is 36 minutes, the half-life for the sample is
(A) 30 minutes
(B) 24 minutes
(C) 20.8 minutes
(D) 14.4 minutes
(E) 6 minutes

Answer : 1(D)

2. Blue light of wavelength 480 nanometers is most strongly reflected off a thin film of oil on a glass slide when viewed near normal incidence. Assuming that the index of refraction of the oil is 1.2 and that of the glass is 1.6. what is the minimum thickness of the oil film (other than zero)?
(A) 150 nm
(B) 200 nm
(C) 300 nm
(D) 400 nm
(E) 480 nm

3. A prototype atomic battery consists of a capacitor with one plate covered with a radioactive film that emits alpha particles with a speed of 2.4 x 10*6 meters/second. What is the emf of this battery?
(The charge-to-mass ratio of an alpha particle is 4.8 x 10*7 coulombs/kilogram.)

(A) 5 kV
(B) 30 kV
(C) 60 kV
(D) 120 kV
(E) 480 kV

Answer : 3.(C) e.m.f = work done/charge = k.e./ charge

4. A particle of mass M disintegrates into two photons. An observer is moving in a direction perpendicular to the photons' momenta, as viewed in the particle's rest frame. In the observer's rest frame, the photons are moving at 90° relative to
one another. Which of the following gives the speed of the observer?
(A) c/4
(B) c/2
(D) c
(E) sqrt(2) * c

Post Reply