未知题型
一列波，在第一种介质中的波长为λ1，在第二种介质中的波长为λ2，已知λ1 =3λ2，则该列波在这两种介质中频率之比和波速之比分别为（）。
- A.1:1;3:1
B.3:1;1:1
C.1:1;1:3
D.1:3;3:1
【参考答案】
A
波由一种介质传到另一种介质的过程中，频率f不变，v1：v2=λ1f：λ2f =λ1：λ2=3：1。
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