理想变压器原线圈接在如图所示的电压上,原副线圈匝数之比为10:1,串在原线圈上的

题型:多选题

问题:

理想变压器原线圈接在如图所示的电压上,原副线圈匝数之比为10:1,串在原线圈上的电流表的示数为1A,则以下叙述正确的是(  )

A.变压器输出功率为200W

B.若n1=100匝,则输出端线圈的磁通量变化率的最大值为2Wb/s

C.副线圈两端的电压表示数20V

D.变压器的输入功率是由发电厂的输出功率决定的

考点:变压器的结构和原理
题型:多选题

具有升颌作用的肌肉有()

A.翼内肌

B.翼外肌

C.颞肌

D.咬肌

E.二腹肌

题型:多选题

农村居民之间发生的土地权属争议案件,可以根据当事人的申请,由( )受理和处理。

A.省国土资源行政主管部门

B.县级人民法院

C.乡土管所

D.乡人民政府

题型:多选题

19世纪60年代出现中外反动势力“合作”的新格局,最主要是因为( )。

A.慈禧太后发动 * * 需要外国支持

B.清政府中的投降派联合外国共同对付抵抗派

C.外国资本主义对中国的侵略的深入使清政府呈现半殖民地化

D.清政府对外国侵略完全放弃了抵抗

题型:多选题

The UN passed a rule in the year 2004 to improve the quality of drink water and reduce deaths caused by drinking unhealthy water each year. The UN has already worked out the specific plan to reduce half of the number, that is, five thousand. The UN announced in the world there are about 1/6 of the world population can't meet the sanitation regulation of drinking water.

The water we drink and use is running short in the world. We all have to learn to stop wasting our quite limited water. One of the steps we should take is to find ways of reusing it. Experiments have already been done on this field. Today in most large cities, fresh water is used only once, then it runs into waste system. But it is possible to pipe the used water to a purifying(净化)factory. There it can be filtered(过滤) and treated with chemicals so that it can be used again , just as it were fresh from a spring. But even large cities purified and reused its water, we still would not have enough. Then we could turn to the oceans. All we would have to do to make use of seawater on earth is to get the salt out of it. This method has already been used in many parts of the world.

47. The way to stop wasting water is to ________ .

A. do experiments with water

B. purify the used water and reuse it

C. use fresh water once again

D. make use of seawater

48. The passage tells us how to reuse the used water. Which is the right order of the process?

a. to have the used water filtered b. to put chemical in it

c. to pipe it to the user

d. to pipe the used water to be purified in a factory.

A. dabc B. bcda C. bdca D. dcba

49. There wouldn't be enough water for us if we didn't ________ .

A. turn to the ocean for more water

B. reuse used water and make use of seawater

C. make fresh water from the seawater

D. take steps to reuse all water on earth

50. The word "it" underlined in the last paragraph refers to ________ .

A. the process of collecting salt from the ocean

B. the process of getting rid of the salt in seawater

C. purified water

D. seawater

题型:多选题

关于木星的四颗伽利略卫星说法错误的是?()

A.木卫四Callisto是伽利略卫星中唯一的一颗非同步自转卫星。

B.木卫一Io表面的火山活动非常剧烈。

C.木卫二Europa冰冻的外壳下很可能存在着液态海洋。

D.木卫三Ganymede是太阳系中体积最大的卫星。

更多题库