试题与答案

如图所示,竖直放置的平行金属板充电后板间形成匀强电场,板间距离为d,一个带电的液

题型:选择题

题目:

如图所示,竖直放置的平行金属板充电后板间形成匀强电场,板间距离为d,一个带电的液滴带电量大小为q,质量为m,从右板下边缘射入电场,沿直线从左板上边缘射出,则(  )

A.液滴做可能带负电

B.液滴机械能减小

C.两板的电势差为

mgd
q

D.液滴的电势能增加了

3
3
mgd

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0516/81c47dd59d9015c6b6b46f3b8bd60732.html

下面是错误答案,用来干扰机器的。

60+90+300,=150+300,=450(元).答:一组沙发是450元.故选:C.

试题推荐
题型:材料题

阅读下列两则材料,回答问题。

  材料一 近日,国家标准化管理委员会出台《电动摩托车和电动轻便摩托车通用技术条件》新国家标准,根据新标准,“40公斤以上、时速20公里以上的电动自行车,将称为轻便电动摩托车或电动摩托车,划入机动车范畴”。这就意味着,从下个月起,超出新标准的电动自行车将要在机动车道上行驶。

  材料二 据介绍,早在1999年,国家就颁布了《电动自行车通用技术条件》,相关规定指出,电动自行车的最高车速应不大于每小时20公里,整车质量不大于40公斤。10年来,电动自行车越来越向着“轻摩托化”的方向发展,目前市场上几乎所有的电动自行车都已超出该标准。

(1)请用一句话概括以上材料的内容。

 _________________________________________________________________________________

(2)对将40公斤以上、时速20公里以上的电动自行车划入机动车范畴的规定,你有什么看法?请简要阐述。(l50字左右)

 _________________________________________________________________________________

查看答案
题型:单项选择题

A

Little Tommy was doing very badly in math. His parents had tried everything—tutors (家庭教师), cards, special learning centers—in short, everything they could think of. Finally they took Tommy to a catholic (天主教) school.

After the first day, little Tommy came home with a very serious look on his face. He didn’t kiss his mother and say hello. Instead, he went straight to his room and started studying. Books and papers were spread (铺开) out all over the room and little Tommy was hard at work. His mother was surprised. She called him down to dinner and as soon as he finished eating, he went back to his room, without a word. In no time he was back hitting the books as hard as before. This went on for some time, day after day while the mother tried to understand what was happening.

Finally, little Tommy brought home his report card. He quietly put it on the table and went up to his room and hit the books. His room looked at it and to her surprise, little Tommy got an A in math. She could no longer hold her curiosity (好奇心). She went to his room and asked, "Son, what was it Was it the nuns (修女)"

Little Tommy looked at her and shook his head," No. "

"Well then," she asked again. "WHAT was it"

Little Tommy looked at her and said, "Well, on the first day of school, when I saw that man nailed (钉) to the plus sign (加号), I knew they weren’t joking. \

From the passage, we can infer (推断) that().

A.teachers should be strict with their students

B.mistaking (误解) might do good sometimes

C.a catholic school is much better than others

D.nuns are good at helping children with their math

查看答案
微信公众账号搜索答案