搜题请搜索小程序“爱下问搜题”
问题 实验题

现有两个小灯泡，灯泡A标有“6V、6W”，灯泡B标有“6V、3W”，它们的电流与电压关系的图象如图所示。将它们串联起来接在电路中，其中一个灯恰好正常发光时，电路在10min内产生的热量是         J。

答案

2400

题目分析：灯泡A的额定电流；灯泡B的额定电流；因只有一灯正常发光，故只能为B灯正常发光；由图可知，此时电路中电流为0.5A；A灯两端的电压为2V；则电路中的总电压U=2V+6V=8V；电路中电流所做的功全部转化为内能；故热量Q=W=UIt=8V×0.5A×10×60s=2400J。

点评：解决本题的关键是熟知串联电路电流的特点：在串联的电路中，各处电流均相等。

单项选择题

As one works with color in a practical, or experimental way, one is impressed by two apparently unrelated facts. Color as seen is a mobile, changeable thing (1) to a large extent on the relationship of the color (2) other colors (3) simultaneously. It is not (4) in its relation to the direct stimulus which (5) it. On the other hand, the properties of surfaces that give (6) to color do not seem to change greatly under a wide variety of illumination color, usually (but not always) looking much the same in artificial light as in daylight. Both of these effects seem to be (7) in large part to the mechanism of color (8) .

When the eye is (9) to a colored area, there is an immediate readjustment of the (10) of the eye to color in and around the area (11) . This readjustment does not promptly affect the color seen but usually does affect the next area to which the (12) is shifted. The longer the time of viewing, the higher the (13) , and the larger the area, the greater the effect will be (14) its persistence in the (15) viewing situation. As indicated by the work of Wright and Schouten, it appears that, at (16) for a first approximation, full adaptation takes place over (17) time if the adapting source is moderately bright and the eye has been in (18) darkness just previously. Also, (19) of the persistence of the effect if the eye is shifted around from one object to another, all of which are at similar brightness or have similar colors, the adaptation will tend to become (20) over the whole eye.

3（）

A.pursued

B.perceived

C.realized

D.conceived
查看答案
论述题

2013年3月17日，国家 * * 习 * * 在十二届人大一次会议闭幕会上称中国梦是人民的梦，要让人民共享人生出彩、梦想成真的机会，要倾听人民的呼声、回应人民的期待。而我们每个人都在追逐自己的梦想，这构成了“中国梦”的一块块基石。“中国梦”的建构，又为个人放飞自己的梦想提供了平台和土壤。习 * * 指出，国家好、民族好，大家才会好。实现中 * * 的伟大复兴是一项光荣而艰巨的事业，需要一代又一代中国人共同为之努力。

结合材料，运用整体与部分的关系原理，说明如何正确处理 “个人梦”和“中国梦”的关系。（10分）
查看答案