25. The length of a bow is L. When it vibrates in the fundamental mode with a length of 2 L, the frequency is f. Taking half of the given length and pulling it to a length of 2L as before, the frequency obtained by vibrating in the basic method is,
(i) 3fo
(iv) √3f
(ii) 6fo
(v) √6fo
(iii) f/3
