已知一电流表的满偏电流为3mA,其内阻为120Ω,要把它改装成量程为6V的电压表

题型:计算题

问题:

已知一电流表的满偏电流为3mA,其内阻为120Ω,要把它改装成量程为6V的电压表。

(1)应串联还是并联电阻?

(2)电阻值是多大?

考点:实验:伏安法测电阻实验:练习使用示波器实验:测绘小灯泡的伏安特性曲线实验:探究影响导体电阻的因素
题型:计算题

消防水系统正常运行压力,稳压泵启停压力,电泵及柴油消防泵联起压力?

题型:计算题

依次在下列各句横线处填入所列出的词语,恰当的一组是______。 ①惩治腐败,打击贪赃枉法,______贪污分子是当前政法工作的首要任务。 ②今天是校庆的日子,多年不见的老同学又______在一起。 ③年轻的父母们不要对自己孩子一味______,这样对孩子的健康成长很不利。 ④上周,学校的校务委员会对这个问题作了最终的______。

A.揭发 汇聚 溺爱 裁决

B.揭露 会聚 宠爱 裁定

C.揭发 会聚 溺爱 裁决

D.揭露 汇聚 宠爱 裁定

题型:计算题
下列加粗词的解释不当的一项是
 [ ]
A.谪守(指古代官吏降职或远调做州郡的长官) 
B.樯倾楫摧(桅倒下,桨断折)               
C.暮冥冥(薄薄的,淡淡的)               
D.异二者之为(有人)                     
胜状(胜景、好景色)   
怀乡(国都)       
物喜(拿,用)     
长烟一空(有时) 
题型:计算题

电流互感器宜安装在串补平台相对高压侧。()

题型:计算题

Children are a relatively modem invention. Until a few hundred years ago they look like adult, wearing grown-up clothes and grown-up expressions, performing grown-up tasks. Children did not exist because the family as we know it had not evolved.
Children today not only exist; they have taken over in no place more than in America, and at no time more than now. It is always Kids Country here. Our civilization is child-centered, child-obsessed. A kid’s body is our physical ideal. In Kids Country we do not permit middle-aged. Thirty is promoted over 50, but 30 knows that soon his time to be overtaken will come.
We are the first society in which parents expect to learn from their children. Such a topsy-turvy situation has come to abort at least in part because, unlike the rest of the world, ours is an immigrant society, and for immigrants the only hope is in the kids. In the Old Country, that is, Europe, hope was in the father, and how much wealth he could accumulate and pass along to his children. In the growth pattern of America and its ever- expanding frontier, the young man was ever advised to GO WEST; the father was ever inheriting from his son. Kids Country may be the inevitable result.
Kids Country is not at all bad. America is the greatest country in the world to grow up in because it is Kids Country. We not only wear kids clothes and eat kids food; we dream kids dreams and make them come tree. It was, after all, a boys’ game to go to the moon.
If in the old days children did not exist, it seems equally true today that adults, as a class, have begun to disappear, condemning all of us to remain boys and girls forever, jogging and doing push-ups against eternity.

In Paragraph 3, "the Old Country" is contrasted with America to show ______ .

A.differences in family size

B.differences in attitudes towards family relations

C.two kinds of geography

D.two different kinds of economic relations between generations

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