Which of the following is TRUE?
a) It is possible for galaxies that are very distant to actually move through space ata speed several times the speed of light.
b) A redshift occurs when a photon loses energy and slows down as itmoves through space.
c) We see distant galaxies as they were billions or even tens of billions ofyears ago.
d) We measure a redshift for roughly half of the galaxies that we observe, and for theothers we measure a blueshift.
e) The center of the universe is located at a point about 200 Mpc from us in the centerof a cluster of galaxies.
Answer: c) We see distant galaxies as they were billions or even tens of billions ofyears ago.
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The sun appears larger at sunset than it does when overhead because of:
1.Scattering of light. 2.Dispersion. 3.Diffraction. 4.Refraction. 5.An optical illusion. 6.None of the above.
A thin metal sheet in the xy plane carries current in the ?y direction. What is the direction of the magnetic field everywhere in the region above the sheet? 
in this case
A. points in the +x direction. B. points in the ?x direction. C. points in the +y direction. D. points in the ?y direction. E. points in the +z direction. F. points in the ?z direction. T. is zero.
A 2.0-m wire carries a current of 15 A directed along the positive x axis in a region where the magnetic field is uniform and given by B = 
mT. What is the resulting magnetic force on the wire?
A.
) NB.
) NC.
) ND.
) NE.
) NCompared to the amount of electric current in the filament of a lamp, the amount of current in the connecting wire is
A) definitely less. B) often less. C) actually more. D) the same. E) incredibly, all of the above