In resonance air-column method, two resonances in the air-column were obtained by lowering the water level. The resonance with the shorter air-column is the first resonance and that with the longer air-column is the second resonance. Then,

Select all that apply

• Option A

  the intensity of the sound heard at the first resonance was more than that at the second resonance.

• Option B

  the prongs of the tuning fork were kept in a horizontal plane above the resonance tube.

• Option C

  the amplitude of vibration of the ends of the prongs is typically around 1 cm .

• Option D

  the length of the air-column at the first resonance was somewhat shorter than 1/4th of the wavelength of the sound in air.