问题 选择题

对爱因斯坦光电效应方程EkW0,下面的理解正确的是(  )

A.只要是用同种频率的光照射同一种金属,那么从金属中逸出的所有光电子都会具有同样的初动能Ek

B.式中的W0表示每个光电子从金属中飞出过程中克服金属中正电荷引力所做的功

C.逸出功W0和极限频率ν0之间应满足关系式W00

D.光电子的最大初动能和入射光的频率成正比

答案

答案:C

爱因斯坦光电效应方程EkW0中的W0表示从金属表面直接逸出的光电子克服金属中正电荷引力做的功,因此是所有逸出的光电子中克服引力做功的最小值,对应的光电子的初动能是所有光电子中最大的,其他光电子的初动能都小于这个值,故A、B错误.若入射光的频率恰好是极限频率,即刚好能有光电子逸出,可理解为逸出的光电子的最大初动能是0,因此有W00,C对.由EkW0可知Ekν之间是一次函数关系,但不是成正比关系,D错误.

阅读理解

阅读表达。

     Even if you really enjoy your job,it's still possible to battle boredom as you work.You may not be able

to make big changes-or change your job-but you can make small adjustments to your routine that can

make every day seem,well,a little less routine.

    1. Switch Your Seat

       Change your outlook at the office by changing your office.Ask your supervisor to help you find a

new desk.Even switching desks with a neighboring coworker can offer a fresh atmosphere.

     If it's not possible to change your location,see if you can change your desk's direction.A new view

can be just as refreshing as a new location.

     2. ________

      Start and end your day in a different way.Consider a new mode of transportation,if it's possible.Take

a subway.Ride a bike on sunny days.Carpool with a coworker.Use a new route to get to your job.You

needn't change it for ever-just long enough to help you escape the boredom

     3. Find a New Work Style

     Sick of attending that longstanding Monday morning meeting?Try to change it to the afternoon.

     If you find yourself feeling most bored in the afternoons,try to arrange to do your favorite tasks then

and tackle less desirable projects in the mornings.

     If you usually communicate with coworkers via email and instant messaging,start dealing with people

face to face.Increased communication with coworkers may help improve your mood.

      4. Get and Set a Goal

      If your work is short of objectives,it's no wonder that work has become boring.Identify a goal and

set an "achieve by" date for it.

     Your_goal_needn't_be_high_as_long_as_you_have_sufficient_enthusiasm_for_it.Perhaps you want

to make a new project.Maybe you'd like to pursue a promotion.Or you may even set a goal of finding a

new job altogether.Whatever it is,actively move toward an objective.

1. What is the purpose of the passage?(within 15 words)

________________________________________________________________________

2. Which sentence in the text is the closest in meaning to the following one?

You will feel bored when you are not working toward something.

________________________________________________________________________

3. Fill in the blank in Paragraph 5 with proper words.(within 8 words)

________________________________________________________________________

4. List three methods of escaping from boredom in your daily life.(within 5 words for each)

①________________________________________________________________________

②________________________________________________________________________

③________________________________________________________________________

5. Translate the underlined sentence in the Last Paragraph into Chinese.

________________________________________________________________________

单项选择题 A型题