题目9单选题
单缝夫琅和费衍射实验中,若波长是<img src="https://tihai-oss-cloud.itihey.com/img/ae3cf6226dc0f51387c762429549f457.png">,缝宽为a=0.6mm,透镜焦距为f=0.4m,则中央明纹的宽度为2<img src="https://tihai-oss-cloud.itihey.com/img/ae3cf6226dc0f51387c762429549f457.png">f/a,其它条纹间距为<img src="https://tihai-oss-cloud.itihey.com/img/ae3cf6226dc0f51387c762429549f457.png">f/a,若屏上距离中点1.4mm的P点观察到衍射明纹,则(1)入射光的波长是多少? 对应的级次( )【教材17-9计算题作业】A. 600nm,3级B. 466nm,3级C. 600nm,4级D. 700nm,2级