由同种材料构成的均匀金属杆abc处于磁感强度B=0.1T的匀强磁场中

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问题填空题

由同种材料构成的均匀金属杆abc处于磁感强度B=0.1T的匀强磁场中，磁场方向垂直纸面向里，如图所示．已知L_ab=L_bc=20cm，当金属杆以10m/s的速度在图中标明的方向运动时，则a、c两点间的电势差是 V，a、b两点间的电势差是 V

答案

0.3 ， 0.2

ac切割磁感线的有效长度为Lab+ Lb c cos60°，由E=BLv得感应电动势为0.3V，ab两点有效长度为Lab，电势差为0.2V

补全对话，情景问答

补全对话。

A:I'm not feeling well. I 1. ______ ( have) a cold.

B:It is cold outside. You should put on more clothes.

A:2. ______ you.3.______ (be) to the hospital yet?

B:Yes, I 4.______ ( go) to see a doctor this moming and he 5.______ ( give) me some medicine.

A:6.______ you 7______ (take) the medi-cine?

B:Yes, I 8.______ ( take) it just now.

A:lt is nothing serious. You should drink plenty of water and get some rest. I think you'll9.______ (be) all right

soon.

B:I hope so. By the way, where is our monitor?

A:She 10.______ ( go) to the play-ground.

单项选择题

下列调查项目中，属于房地产消费动机调查内容的是（）

A.地段要求

B.购买意向

C.户型要求

D.经济收入水平