Question

In a resonance column experiment, the length of air column at $1^{st}$ resonance is measured to be 13.1 cm with a possible indeterminate error of 0.1 cm. With the same scale, the $2^{nd}$ resonance occurs at 39.2 cm. The possible wavelength of the sound can be

• A. 52.2 cm
• B. 52.4 cm
• C. 52.6 cm
• D.
  52. 0 cm

Answer 1

Answer: (A)

52.2 cm

Answer 2

Explanation:
For a closed air column, successive resonances occur with a difference of half a wavelength:
  λ/2 = (L₂ - L₁)
Given L₁ = 13.1 cm and L₂ = 39.2 cm, the difference is
  39.2 cm – 13.1 cm = 26.1 cm
Thus,
  λ = 2 × 26.1 cm = 52.2 cm