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Physics · PYQ NEET UG 2019(2)
हिन्दीA tuning fork with frequency \( 800\text{ Hz} \) produces resonance in a resonance column tube with upper end open and lower end closed by water surface. Successive resonance are observed at lengths \( 9.75\text{ cm} \), \( 31.25\text{ cm} \) and \( 52.75\text{ cm} \). The speed of sound in air is,
Correct answer · Option 4
\( 344\text{ m/s} \)
Explanation
The fundamental length difference \( \frac{\lambda}{2} = l_2 - l_1 = 31.25 - 9.75 = 21.5\text{ cm} = 0.215\text{ m} \). Wavelength \( \lambda = 0.43\text{ m} \). Speed \( v = f\lambda = 800 \times 0.43 = 344\text{ m/s} \).
