Question

Which one of the following cannot be the unit of frequency of a sound wave?
1. dB
2. s^-1
3. Hz
4. min^-1

Answer 1

Correct Answer - Option 1 : dB

CONCEPT:

• Frequency (ν): The number of waves that pass a given point per second is called frequency.
  • The unit of frequency is vibration per second or Hertz.

• Time period (T): The time taken to complete one full oscillation or cycle by the Wave is called the time period.

  • The SI unit of the time period is second (s).
• The relationship between time period and frequency is given as:

Time period (T) = 1/ν 

EXPLANATION:

• A sound's loudness is measured in decibels (dB). Therefore option 1 can't be the unit of frequency of a sound wave.
  • The loudness of sound is determined by the intensity of the sound waves.
  • Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB), Phon, and Bel. Therefore option 3 is correct.​​​

• s^-1, Hertz (Hz), and min^-1 is the unit of frequency.