中学生网络课堂本课配套习题挑战模式1/5
直流电动机中，可以使线圈一到平衡位置就自动改变线圈中电流方向的装置是（ ）
| A: 线圈 |
| B: 铜环 |
| C: 换向器 |
| D: 电刷 |
- 提示1：PHA+55S15Yqo5py655qE57uT5p6EPC9wPg==
- 提示2：PHA+5o2i5ZCR5Zmo55qE5L2c55So5piv57q/5ZyI5Yia6L2s6L+H5bmz6KGh5L2N572u5pe277yM6Ieq5Yqo5pS55Y+Y57q/5ZyI5Lit55qE55S15rWB5pa55ZCRPC9wPg==
- 答案：Qw==
PHA+55S15Yqo5py655Sx56OB5L2T44CB57q/5ZyI44CB5o2i5ZCR5Zmo44CB55S15Yi357uE5oiQ77yM5o2i5ZCR5Zmo55qE5L2c55So5bCx5piv5Zyo57q/5ZyI5Yia6L2s6L+H5bmz6KGh5L2N572u5pe277yM6Ieq5Yqo5pS55Y+Y57q/5ZyI5Lit55qE55S15rWB5pa55ZCR77yM5pWFQ+ato+ehri48L3A+
本课配套习题挑战模式2/5
要想使一台直流电动机的转速增大一些，下列方法中不可能达到目的的是（ ）
| A: 增大线圈中的电流强度 |
| B: 更换电源，用输出电压较高的直流电源 |
| C: 将磁体的磁极对调一下 |
| D: 再增加一个磁体，使该磁体产生的磁场与原有磁场方向一致 |
- 提示1：PHA+55u05rWB55S15Yqo5py655qE6L2s6YCf5LiO56OB5Zy65by65byx77yM55S15rWB5by65byx5pyJ5YWzPC9wPg==
- 提示2：PHA+5LqG6Kej55S15Yqo5py655qE5Y6f55CG77yM5Y+K5Y+X5Yqb5aSn5bCP5ZKM5pa55ZCR55qE5b2x5ZON5Zug57SgPC9wPg==
- 答案：Qw==
PHA+6KaB5oOz5aKe5aSn55u05rWB55S15Yqo5py655qE6L2s6YCf77yM6ZyA6KaB5aKe5aSn57q/5ZyI5Lit55qE55S15rWB77yM5oiW5aKe5by656OB6ZOB55qE56OB5oCn77yM5q+U5aaC5Zyo57q/5ZyI5Lit5o+S5YWl6ZOB6Iqv44CB5aKe5by65Y6f5p2l55qE56OB5Zy677yM5a+56LCD55S15rqQ5Lik5p6B5oiW56OB6ZOB5Lik5p6B5Y+q6IO95pS55Y+Y55S15Yqo5py655qE6L2s5Yqo5pa55ZCRLuaVhemAiUMuPC9wPg==
本课配套习题挑战模式3/5
| A: 电磁感应现象 |
| B: 电流的热效应 |
| C: 通电导体周围存在磁场 |
| D: 通电导体在磁场中受力 |
- 提示1：IOaOjOaPoeeUteWKqOacuueahOWOn+eQhg==
- 提示2：IOazqOaEj+eUteWKqOacuuWSjOWPkeeUteacuueahOWOn+eQhuWMuuWIqw==
- 答案：RA==
55S15Yqo5py655qE5Z+65pys5bel5L2c5Y6f55CG5piv77ya6YCa55S15a+85L2T5Zyo56OB5Zy65Lit5Y+X5Yqb77yb55S156OB5oSf5bqU5piv5Y+R55S15py65Y6f55CG77yb6YCa55S15a+85L2T5ZGo5Zu05a2Y5Zyo56OB5Zy65piv5aWl5pav54m55a6e6aqM77yb6YCa55S15a+85L2T5Y+R54Ot5piv55S16IO96L2s5YyW5Li65YaF6IO9LiDmlYVBQkPplJnor68uIOaVhemAiUQuIA==
本课配套习题挑战模式4/5
一台组装齐全的直流电动机模型，接通电源后电机不转，用手拨动一下转子后，线圈转子就正常转动起来，则它开始时不转的原因可能是（ ）
| A: 线圈内部断路 |
| B: 电刷与换向器接触不良 |
| C: 磁铁的磁性不强，或线圈中的电流不够大 |
| D: 线圈正好处于平衡位置 |
- 提示1：PHA+57q/5ZyI5aSE5Zyo5bmz6KGh5L2N572u5pe277yM5rKh5pyJ55S15rWB6YCa6L+HPC9wPg==
- 提示2：PHA+57q/5ZyI5Lit5peg55S15rWB77yM56OB5Zy65bCx5LiN6IO95a+557q/5ZyI5pyJ5Yqb55qE5L2c55SoPGJyPjwvcD4=
- 提示3：PHA+5LqG6Kej55S15Yqo5py65bel5L2c5Y6f55CGPC9wPg==
- 答案：RA==
PHA+5Zyo55S15py65LiN6L2s5pe277yM5Y+q5piv5Yqo5LqG5LiA5LiL6L2s5a2Q5bCx6L2s5Yqo6LW35p2l77yM6K+05piO5LiN5piv55S15Yqo5py657q/5ZyI5pat6Lev55qE5pWF6Zqc77yM5Y+q6IO95piv57q/5ZyI6L2s5YGc5Zyo5bmz6KGh5L2N572uLiDmlYXpgIlELjwvcD4=
本课配套习题挑战模式5/5
下列能改变电动机转动方向的是（ ）
| A: 改变电流的大小 |
| B: 改变磁场的强弱 |
| C: 改变电流的方向 |
| D: 同时改变电流方向和磁场方向 |
- 提示1：PHA+55S15Yqo5py655qE5Y6f55CGPC9wPg==
- 提示2：PHA+57q/5ZyI6L2s5Yqo5pa55ZCR5LiO56OB5Zy65pa55ZCR5ZKM55S15rWB5pa55ZCR5pyJ5YWzPC9wPg==
- 提示3：PHA+5pS55Y+Y55S15Yqo5py655qE6L2s5Yqo5pa55ZCR55qE5Lik56eN5pa55rOVPC9wPg==
- 答案：Qw==
PHA+QeOAgeeUtea1geeahOWkp+Wwj+S4jueUteWKqOacuueahOi9rOWKqOaWueWQkeaXoOWFs++8jOaJgOS7peS4jeato+ehri4gQuOAgeejgeWcuueahOW8uuW8seS4jueUteWKqOacuueahOi9rOWKqOaWueWQkeaXoOWFs++8jOaJgOS7peS4jeato+ehri4gQ+OAgeWPquaUueWPmOeUtea1geaWueWQke+8jOeUteWKqOacuui9rOWKqOaWueWQkeaUueWPmO+8jOaJgOS7pemAiemhueato+ehri4gROOAgeWQjOaXtuaUueWPmOeUtea1geaWueWQkeOAgeejgeWcuuaWueWQke+8jOeUteWKqOacuui9rOWKqOaWueWQkeS4jeWPmO+8jOaJgOS7peivpemAiemhueS4jeato+ehri4g5pWF6YCJQy48L3A+
