NTA Abhyas JEE Main2020PhysicsWaves and SoundPractice
A uniform wire of length L and diameter D and density ρ is stretched under a tension T . The correct relation between its fundamental frequency f , the length L and the diameter D is
Options
- Af ∝ 1 L D 2
- Bf ∝ 1 D 2
- Cf ∝ 1 L D
- Df ∝ 1 L D
Correct answer
C. f ∝ 1 L D
Step-by-step solution
Since, we know, Frequency, f = n 2 L T m Where, T = tension in the string, L = Length of the string And m = linear mass density of the string. ∴ m = M L = π D 2 2 ⋅ L ⋅ ρ L = π D 2 ρ 4 Thus, f = 1 2 L ⋅ T π D 2 ρ 4 For fundamental frequency, n = 1 f = 1 2 L D 2 T π ρ = 1 L D ⋅ T π ρ f ∝ 1 L D