Question:

A sonometer wire of length 1.5m is made of steel. The tension in it produces an elastic strain of 1%. Find the fundamental frequency.

770Hz

188.5Hz

200.5Hz

178.2Hz

Fundamental frequency f = (1/2l)√(T/μ) = (1/2l)√(stress/ρ)
= (1/2 × 1.5) √(22 × 10¹¹ × 10⁻⁶ / 77 × 10³)
= 10³ × 0.17817 = 178.2 Hz