喷墨打印机的简化模型如图所示，重力可忽略的墨汁微滴，经带电室_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

喷墨打印机的简化模型如图所示，重力可忽略的墨汁微滴，经带电室带负电后，以相同的速度v垂直匀强电场飞入极板间，最终打在纸上，则不同微滴在极板间电场中

A．向负极板偏转

B．加速度一定相同

C．运动时间一定相同

D．竖直方向偏移的距离一定相同

答案

答案：C

题目分析：液滴带负电，故向正极偏转，A错；不同的信号输入对应液滴打在纸上的不同位置，故可知液滴的电荷量、加速度、竖直偏转位移不一定相同，BD错；液滴的运动时间为全程水平位移除以水平速度，故C正确。

完形填空

Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.

A. desperation	B. authorities	C. diligently	D. confusion	E. enrolled
F. violently	G. financial	H. conclusion	I. devoted	J. graduation

Seventeen years ago, when I was in military college, I was known as “the worrying wreck from Virginia Tech”. I worried so ____小题1:_____ that I often became ill. In _____小题2:_____, I poured out my troubles to Professor Baird, professor of business administration. The fifteen minutes that I spent with Professor Baird did more for my health and happiness than all the rest of the four years I spent in college. “Jim,” he said, “you ought to sit down and face the facts. If you _____小题3:_____ half as much time and energy to solving your problems as you do to worrying about them, you wouldn’t have any worries. ”
I figured that I had failed physics because I had no interest in the subject. But now I changed my attitude. I said to myself, “If the college _____小题4:_____ demand that I pass my physics examination before I obtain a degree, who am I to question their wisdom?”
So I ______小题5:____ for physics again. This time I passed because instead of wasting my time in worrying about how hard it was, I studied _____小题6:_____.
I solved my ____小题7:_____ worries by taking on some additional jobs, such as selling punch at the college dances, and by borrowing money from my father, which I paid back soon after ____小题8:______.
As I look back at it now, I can see that my problem was one of _____小题9:_____, a lack of willingness to find the causes of my worry and face them realistically.

判断题

回转减速机应每运转500小时检查一次，必须保持有足够的预紧力。