问题 选择题

如图所示,圆环形导体线圈a平放在水平桌面上,在a的正上方固定一竖直螺线管b,二者轴线重合,螺线管与电源和滑动变阻器连接成如图所示的电路。若将滑动变阻器的滑片P向上滑动,下面的说法中正确的是

 

A.穿过线圈a的磁通量变大

B.线圈a有收缩的趋势

C.线圈a中将产生俯视顺时针方向的感应电流

D.线圈a对水平桌面的压力FN将增大

答案

答案:C

划片向上滑动,滑动变阻器电阻增大,流过通电螺线管的电流减小,穿过闭合线圈磁通量减小,根据右手螺旋定则,螺线管下部为N级,由楞次定律可判断闭合线圈电流俯视为顺时针方向,C对;由“安培力的效果总是阻碍磁通量的变化”可知闭合线圈有扩张的趋势,受到的通电螺线管的作用力为引力,线圈a对水平桌面的压力FN将减小,ABD错;

阅读理解

“Whatever",totally tops most annoying word in the poll (民意测验).So, you know, it is what it is, but Americans are totally annoyed by the use of‘ whatever"’ in conversations. The popular term of indifference (不感兴趣)was found most annoying in conversations by 47 percent of the Americans surveyed in a Marist College poll on Wednesday.

“Whatever"easily beat out “you know",which especially annoyed a quarter of interviewers. The other annoying expressions were "anyway"(at 7 percent), “it is what it is” (11percent) and “at the end of the day(2 percent).

"Whatever" is an expression with staying power It left everyone a deepimpression in the song by Nirvana (“oh well, whatever, never mind”)in 1991 and was popularized by the Valley Girls in the film “Clueless”,later that decade. It is still commonly used, often by younger people.

It can be a common argument-ender or a signal of indifference. And it can really be annoying. The poll found "whatever" to be consistently(始终地) disliked by Americans regardless of their race, sex, age, income or where they live.

“It doesn't surprise me because ‘whatever’,is in a special class, probably, said Michael Adams, author of “Slang(俚语)~The People's Poetry" and an associate professor of English at Indiana University. "It's a word that -and it depends on how a speaker uses it -can suggest being not worthy of attention or respect.” Adams, who didn't take part in the poll and is not annoyed by "whatever," points out that its use is not always negative. “It can also be used in place of other neutral(中性的)phrases that have fallen out of favor, like ‘six of one, half dozen of the other’ ” he said. However, he also noted that the negative meaning of the word might explain why “whatever” was judged more annoying than the ever-popular “you know”.

小题1:Which tops second among the annoying expression according to the passage?'

A.Whatever.

B.You know

C.Anyway.

D.It is what it is.小题2:What can we know about the word "whatever"?

A.It became popular because of Nirvana.

B.It can be commonly used at the beginning of an agreement.

C.Old people like it while young people don't.

D.Almost half of the Americans surveyed disliked it.小题3:In Adams' opinion, the reason why “whatever”, was judged more annoying may be that_____.

A.most of the people don't like it

B.it can be used in place of other neutral phrases

C.it carries certain negative meaning sometimes

D.the poor don't like it小题4:Which of the following statements is true?

A.Adams is not only a writer but also a professor.

B.“Whatever” is a signal of concern.

C.Adams is angry at the word “whatever”

D."Whatever" will be replaced by "You know”

单项选择题