Download Old Physics GRE Problems Based on content from Chapter 2 of your

Old Physics GRE Problems Based on content from Chapter 2 of your Text
1. If the total energy of a particle of mass m is equal to twice its rest energy, then the magnitude of the
particle’s relativistic momentum is
A. mc/2
√
B. mc/ 2
C. mc
√
D. 3mc
E. 2mc
2. A particle leaving a cyclotron has a total relativistic energy of 10 GeV and a relativistic momentum of
8 GeV/c. What is the rest mass of this particle?
A. 0.25 GeV/c2
B. 1.20 GeV/c2
C. 2.00 GeV/c2
D. 6.00 GeV/c2
E. 16.0 GeV/c2
3. Which of the following statements most accurately describes how an electromagnetic field behaves under
a Lorentz transformation?
A. The electric field transforms completely into a magnetic field.
B. If initially there is only an electric field, after the transformation there may be both an electric
and magnetic field.
C. The electric field is unaltered.
D. The magnetic field is unaltered.
E. It cannot be determined unless a gauge transformation is also specified.
4. If a newly discovered particle X moves with a speed equal to the speed of light in a vacuum, then which
of the following must be true?
A. The rest mass of X is zero.
B. The spin of X equals the spin of a photon.
C. The charge of X is carried on its surface.
D. X does not spin.
E. X cannot be detected.
5. The measured index of refraction of x-rays in rock salt is less than one. This is consistent with the
theory of relativity because
A. relativity deals with light waves traveling in a vacuum only.
B. x-rays cannot transmit signals.
C. x-ray photons have imaginary mass.
D. the theory of relativity predates the development of solid-state physics.
E. the phase velocity and group velocity are different.
6. A free electron (rest mass me = 0.5 MeV/c2 ) has a total energy of 1.5 MeV. Its momentum p in units
of MeV/c is about
A.
B.
C.
D.
E.
0.86
1.0
1.4
1.5
2.0
7. A monoenergetic beam consists of unstable particles with total energies 100 times their rest energy. If
the particles have rest mass m, their momentum is most nearly:
A.
B.
C.
D.
E.
mc
10 mc
70 mc
100 mc
104 mc
8. What is the speed of a particle having a momentum of 5 MeV/c2 and a total relativistic energy of 10
MeV?
A. c
B. 0.75c
C. √13 c
D.
E.
1
2c
1
4c
9. A lump of clay whose rest mass is 4 kilograms is traveling at three-fifths the speed of light when it
collides head-on with an identical lump going the opposite direction at the same speed. If the two lumps
stick together and no energy is radiated away, what is the mass of the composite clump?
A.
B.
C.
D.
E.
4 kg
6.4 kg
8 kg
10 kg
13.3 kg
10. An electron has total energy equal to four times its rest energy. The momentum of the electron is
A.
B.
C.
D.
E.
m c
√e
2m c
√ e
15me c
4me c
√
2 15me c
11. A particle of mass M decays from rest into two particles. One particle has mass m and the other particle
is massless. The momentum of the massless particle is:
A.
B.
C.
D.
E.
(M 2 −m2 )c
4M
(M 2 −m2 )c
2M
(M 2 −m2 )c
M
2(M 2 −m2 )c
M
4(M 2 −m2 )c
M
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