A particle with electric<br/>charge is fired into a region of space wh

1.A particle with electric charge is fired into a region of space where the electric field is zero. It moves in a straight line. Can you conclude that the magnetic field in that region is zero?( )选项： A:No; an observation of an object with electric charge gives no information about a magnetic field. B:Yes, you can. C:No; the field might be parallel to the particle’s velocity. D:No; the field might be perpendicular to the particle’s velocity. E:No; the particle might need to have charge of the opposite sign to have a force exerted on it.

2.A charged particle moves through a region of space that has both a uniform electric field and a uniform magnetic field. In order for the particle to move through this region at a constant velocity,选项： A: the electric and magnetic fields must point in the same direction.; B:the electric and magnetic fields must point in opposite directions.; C:the electric and magnetic fields must point in perpendicular directions.; D:The answer depends on the sign of the particle’s electric charge.

3.One reason why we know that magnetic fields are not the same as electric fields is because the force exerted on a charge +q 选项： A、is in opposite directions in electric and magnetic fields. B、is in the same direction in electric and magnetic fields. C、is parallel to a magnetic field and perpendicular to an electric field. D、is parallel to an electric field and perpendicular to a magnetic field. E、is zero in both if the charge is not moving.

4.A charged particle is moving in a constant magnetic field. Assume that the magnetic field is not parallel or antiparallel to the velocity. Concerning the magnetic force exerted on the particle, which of the following statements is false?选项： A:It does no work on the particle.; B:It may increase the speed of the particle.; C:It may change the velocity of the particle.; D:It can act only on the particle while the particle is in motion.

5.1. A charged particle is traveling through a uniform magnetic field. Which of the following statements are true of the magnetic field? 选项： A、It exerts a force on the particle parallel to the field. B、It exerts a force on the particle along the direction of its motion. C、It increases the kinetic energy of the particle. D、It exerts a force that is perpendicular to the direction of motion.

6.The most important reason for you to write literature review in an
article is to ____. 选项： A、show
that you have studied a lot in this field B、introduce
the background knowledge about this field C、show
your comprehensive skill when reviewing what previous scholars have
done D、find
a gap or something contradictory in the previous studies to justify
your research

7.About Gauss's law, which of the following statements is TRUE? 选项： A、If the electric flux through a closed surface is zero, there must be no charge inside the closed surface. B、If there is no charge inside the surface, the electric field inside the surface is zero. C、If the electric field inside the closed surface is uniform, there is no charge inside the closed surface. D、If there is no net charge inside the surface, the electric field over the enclosed surface must be zero.

8.In a certain region of space, the electric field is uniform. It can be proved that the volume charge density in the region must be zero based on the Gauss's law. 选项： A、正确 B、错误

9.In a certain region of space, the electric field is zero. From this fact, what can you conclude about the electric potential in this region? 选项： A、It is zero. B、It does not vary with position. C、It is positive. D、It is negative. E、None of those answers is necessarily true.

10.In a certain region of space, the electric potential is +2 V everywhere along the x axis. From this information, you can conclude that the x component of the electric field in this region is: A: zero. B: in the positive x direction. C: in the negative x direction.

11._______________,
she couldn’t get the door open. 选项： A、As
she might try B、She
might as try C、Try
as she might D、Might
as she try

12.What is the
benefit from serving as a reviewer for a journal or conference? 选项： A、Keep one up in
the field. B、Maintain critical
skill. C、Enhance
curriculum vitae for students. D、All the above.

13.The
best title for the passage might be “__()____”? 选项： A、One
Man’s Meat is Another Man’s Poison B、Foods
and Cultures C、Snail
and Octopus D、People
Are Illogical in Front of Delicacies

14.If
two particles have equal momenta, are their kinetic energies equal? (
) 选项： A、yes,
always B、no,
never C、no,
except when their speeds are the same D、yes,
as long as they move along parallel lines

15.(2016.24)

A proton moves with constant non-zero velocity in a region of space that has a uniform magnetic field directed into the plane of the page. The proton moves directly up the plane of the page. What is the direction of the electric field in this region of space? Ignore gravity.

选项： A:

To the left

B:

To the right

C:

Down the plane of the page

D:

Up the plane of the page

E:

There is no electric field necessary