Moderate

An air column in a tube 32 cm long closed at one end, is in resonance with; a tuning fork. The air column in another tube, open at both ends of length 66cm is in resonance with another tuning fork. When these two tuning forks are sounded together, they produce 8 beats per second then the frequencies of the two tuning forks are. (Consider fundamental frequencies only)

Correct answer: C. 264hz. 256 Hz

  • A. 250 Hz. 258 Hz
  • B. 240 Hz. 248 Hz
  • C. 264hz. 256 Hz
  • D. 280 Hz. 272 Hz

Explanation

Resonance in closed and open tubes:In a closed tube, the air column resonates at its fundamental frequency and its odd harmonics, which is when the length of the air column is equal to a quarter of the wavelength, three-quarters of the wavelength, five-quarters of the wavelength, and so on.In an open tube, the air column resonates at its fundamental frequency and its even harmonics, which is when the length of the air column is equal to half the wavelength, a full wavelength, one and a half wavelengths, and so on.Calculating the wavelengths shown below

Last updated

About Waves

Progressive waves transfer energy through oscillations, with wavelength, frequency, amplitude and wave speed related by v = fλ; sound speed depends on the medium. Superposition produces interference and stationary waves in strings and organ pipes, while simple harmonic motion describes the oscillation itself and must be distinguished from wave propagation.

Practise Waves

1,281 free Waves MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Physics questions like this

Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions