空间电角度<imgwidth="32"height="30"src="http://wljy.whut.edu.cn:80/uploadfiles/word/DJYTFD.files/DJYTFD29245.png">与机械角度β之间的关系为()
①
<imgwidth="87"height="43"src="http://wljy.whut.edu.cn:80/uploadfiles/word/DJYTFD.files/DJYTFD29371.png">
②
<imgwidth="134"height="43"src="http://wljy.whut.edu.cn:80/uploadfiles/word/DJYTFD.files/DJYTFD29492.png">
③
<imgwidth="134"height="43"src="http://wljy.whut.edu.cn:80/uploadfiles/word/DJYTFD.files/DJYTFD29611.png">