题目8单选题
交流电磁铁的衔铁吸合后与吸合前比较,磁通<img src="https://tihai-oss-cloud.itihey.com/img/3621bb822351259f5fcaaa9eb6e09d63.png">和磁阻<img src="https://tihai-oss-cloud.itihey.com/img/1132712de3838df121bfb0e43da5c5be.png">的变化情况是( )A. <img src="https://tihai-oss-cloud.itihey.com/img/3621bb822351259f5fcaaa9eb6e09d63.png">增大,<img src="https://tihai-oss-cloud.itihey.com/img/1132712de3838df121bfb0e43da5c5be.png">不变B. <img src="https://tihai-oss-cloud.itihey.com/img/3621bb822351259f5fcaaa9eb6e09d63.png">不变,<img src="https://tihai-oss-cloud.itihey.com/img/1132712de3838df121bfb0e43da5c5be.png">增大C. <img src="https://tihai-oss-cloud.itihey.com/img/3621bb822351259f5fcaaa9eb6e09d63.png">不变,<img src="https://tihai-oss-cloud.itihey.com/img/1132712de3838df121bfb0e43da5c5be.png">减小D. <img src="https://tihai-oss-cloud.itihey.com/img/3621bb822351259f5fcaaa9eb6e09d63.png">减小,<img src="https://tihai-oss-cloud.itihey.com/img/1132712de3838df121bfb0e43da5c5be.png">不变