Question

The fundamental frequency of a sonometer wire is n. If the tension is made 3 times and length and diameter are also increased 3 times, the new frequency will be __________

(a) 3n

(b) n/3√3

(c) n/3

(d) √3 n

The question was posed to me in an online interview.

My doubt stems from Progressive Waves in division Waves of Engineering Physics I

Answer 1

Right option is (b) n/3√3

To explain I would say: n=1/LD×√(T/πρ)

n^‘=1/(3L×3D)×√(3T/πρ)=√3/9×n=1/(3√3) n.