为了监测变电站向外输电情况，要在变电站安装互感器，其接线如图所示.两变压器匝数分别为n1、n2和n3、n4,a和b是交流电表.则（ ）
A．n1＞n2
B．n3＞n4
C．a为交流电流表，b为交流电压表
D．a为交流电压表，b为交流电流表
AD
由电路连接方式可知，左图是电压互感器，把高电压经过变压器降压后测量，所以n1＞n2,a为交流电压表.右图为电流互感器，把大电流经过变压器减为小电流再测量，所以n3＜n4,b为交流电流表.
| 用方框中所给词的适当形式填空 | |
2. I can't come. I __________ a really busy day. 3. Mr. Green likes to __________ sandwiches with lettuce. 4. Let's __________ some banana smoothie. 5. __________ some more salt to the popcorn, please. 6. You have to __________ the banana before eating lt. 7. Can you help me __________ these tomatoes? 8. Don't __________ waste water into the river. 9. Next you need to __________ all these things into the blender. 10. Finally, __________ on the blender and you'Il get some fruit salad. |