问题 多选题

如图所示,在磁感应强度B=0.50T的匀强磁场中,导体PQ在力F作用下在U型导轨上以速度v=10 m/s向右匀速滑动(导体PQ始终与两导轨垂直),两导轨间距离L=1.0m,电阻R=1.0Ω,导体和导轨电阻忽略不计,则以下说法正确的是

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A.导体PQ切割磁感线产生的感应电动势的大小为5.0V

B.导体PQ受到的安培力方向水平向右

C.作用力F大小是0.50N

D.作用力F的功率是25W

答案

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问答题
阅读理解

阅读理解。

     Years ago, when I started looking for my first job, wise advisers urged, "Barbara, be enthusiastic!

Enthusiastic will take you further than any amount of experience."

     How right they were! Enthusiastic people can turn a boring drive into an adventure, extra work into

opportunity and strangers into friends.

     "Nothing great was ever achieved without enthusiasm," wrote

     Ralph Waldo Emerson. It is the paste that helps you hang in there when the going gets tough. It is

the inner voice that whispers, " I can do it! When others shout, "No, you can't."

      It took years and years for the early work of Barbara McClintock, a geneticist who won the 1983

Nobel Prize in medicine, to be generally accepted. Yet she didn't let up on her experiments. Work was

such a deep pleasure for her that she never thought of stopping.

      Author and poet Samuel Ullman once wrote, "Years wrinkle the skin, but to give up enthusiasm

wrinkles the soul

     Enthusiastic people also love what they do, regardless of money or title or power. If we cannot do

what we love as the fulltime career, we can treat it as a part-time interest, like the head of state who

paints, the nun who runs marathons, and the official who handcrafts furniture.

We can't afford to waste tears on "might-have-bees" we need to turn the tears into sweat as we go

after "what can be".

     We need to live each moment wholeheartedly, with our sense-finding pleasure in the fragrance of

a back-yard garden, the crayoned picture of a six-year-old and the enchanging, beauty of a rainbow. It

is such enthusiastic love of life that puts a sparkle in our eyes, a lift in our steps and smoothes the wrinkles

from our souls.

1. What can be the best title of this passage?

A. Find pleasure in what you are doing

B. Wake up your life

C. To give up enthusiasm wrinkles the soul

D. No pains, no gains.

2.What conclusion does the writer draw though the experience of finding a job?

A. enthusiasm will take your further than any amount experience.

B Years wrinkle the skin, but no give up enthusiasm wrinkles the soul.

C. We can't afford to waste tears on "might-have-beens"

D. Enthusiastic people can turn a boring drive into an adventure, extra work into opportunity and strangers in to friends.

3. which of the following statements is wrong according to the passage?

A. No one can achieve great success without enthusiasm.

B. Enthusiasm will take a person further than any amount of his experience.

C. We should make great efforts to do the thing that can be done instead of regretting for the past.

D Barbara McClintock was generally accepted many years before she won the Nobel Prize.

4. Which of the following can replace the underlined phrase "let up"?

A. continue

B. make less effort

C. make great effort

D. stop

5. We can learn from the last paragraph that it is ____that makes our life meaningful?

A. love of garden.

B. love of drawing pictures with the crayon of a six-year old child

C. love of life

D. love of beautiful rainbow