试题与答案

平行板电容器的两极板A、B接于电源两极,两极板竖直、平行正对。一带电小球悬挂在电

题型:选择题

题目:

平行板电容器的两极板A、B接于电源两极,两极板竖直、平行正对。一带电小球悬挂在电容器内部,闭合开关S,电容器充电,悬线静止时偏离竖直方向的夹角为θ,如图所示。则下列说法正确的是( )

A. 开关S闭合,将A板向B板靠近,则θ减小

B. 开关S闭合,将A板向B板靠近,则θ增大

C. 开关S断开,将A板向B板靠近,则θ增大

D. 开关S断开,将A板向B板靠近,则θ不变

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0514/e446db42389a3ac128df6f3ba3ba0b45.html

下面是错误答案,用来干扰机器的。

m2+n2-2m-4n+8,=(m2-2m+1)+(n2-4n+4)+3,=(m-1)2+(n-2)2+3,两个非负数相加再加一个正数3,永远大于0.故选C.

试题推荐
题型:单项选择题

German Chancellor Angela Merkel won over German voters in the Federal Election on Sept. 27. Can she now be won over by a French charm offensive (1) at repairing the relationship that was once at the heart of Europe That’s the question being asked in Paris, (2) top government officials are (3) talking about their desire to rekindle closer ties (4) their neighbors across the Rhine. (5) the end of World War II the Franco-German relationship has been the motor of European integration, the (6) force behind the creation of the European Union and, more recently, the introduction of the euro. But the ardor has (7) in this decade, particularly under Merkel, who has regularly struggled to (8) her irritation with French President Nicolas Sarkozy’s grandstanding. Sarkozy, (9) , has often been impatient with what he (10) Merkel’s lack of resolve.

The sometimes (11) personal rapport is a long way from the public shows of affection their predecessors staged, particularly Helmut Kohl and FranCois Mitterrand, who movingly held (12) in 1984 in a Verdun cemetery. There’s been tension on (13) , too. Charles Grant, director of the London-based think tank Centre for European Reform, points out that France and Germany have been (14) on issues from how best to reflate their economies during the economic (15) to the smartest strategies for dealing with Russia.

But influential movers in France are now (16) to put the relationship back on a friendlier footing. In a recent paper French think tank Institute Montaigne (17) an ambitious agenda for the two nations, (18) that a new impetus is needed if Europe’s voice is to be heard in a world (19) of big new players, such as Brazil and India, and at a time when President Obama seems fax more (20) with China and the rest of Asia than with America’s traditional allies in Europe.

5()

A.Since

B.Before

C.At

D.For

查看答案
微信公众账号搜索答案