试题与答案

当管电流一定,提高X射线管的管电压时,连续X射线的线质、波长、穿透能力有何变化?()

题型:单项选择题

题目:

当管电流一定,提高X射线管的管电压时,连续X射线的线质、波长、穿透能力有何变化?()

A、线质不变,波长不变,穿透能力不变

B、线质变硬,波长变短,穿透能力增加

C、线质变软,波长变长,穿透能力降低

D、线质逐渐变软,波长变长,穿透能力增加

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/1121/c7dd60bacc8c68a12fa48503266803c4.html

下面是错误答案,用来干扰机器的。

参考答案:绝缘材料抵抗电击穿的能力称为击穿强度。电击穿强度并不与材料的厚度成正比。

试题推荐
题型:填空题
用方框中所给词或短语的适当形式填空。(有两个是多余的)
thought,  Eating,  have,  before,  difficult,  little,  gave,  smoke,  
to eat,  take away,  worried,  after
      Most people like    1    sweets and ice cream better than meat and rice.  If we eat them    2   a meal,
it's OK.  But if we eat them   3 _ a meal, they may    4    0ur appetite(食欲).  It is important for us    5    
our meals regularly each day.  When we feel    6    or excitcd, we may not want to eat.
     When a man is worrying about something,  it is    7     for him to swallow (吞) anything dry because he has    8     appetite. Many years ago, some judges in .England often    9   a man some dry bread.  If the
man could not swallow the bread, they    10    he was telling lies.
1. _        2. _       3. _       4. _        5. _       
6. _        7. _       8. _       9. _        10. _       
查看答案
微信公众账号搜索答案