What is the unit of frequency?

What is the unit of frequency?

• A. Hertz
• B. Decibel
• C. Pascal
• D. Watt

Answer: (A)

Frequency is the number of times a wave completes a cycle each second. The unit that expresses this rate is the Hertz (Hz), where 1 Hz equals 1 cycle per second. In ultrasound, knowing frequency helps you understand image quality because higher frequencies provide better detail (resolution) but don’t penetrate as deeply due to greater attenuation. The other units measure different quantities: decibels measure a ratio on a logarithmic scale (often used for sound intensity levels), pascals measure pressure, and watts measure power. None of those quantify how often a wave cycles per second, which is why Hertz is the correct unit.

Frequency is the number of times a wave completes a cycle each second. The unit that expresses this rate is the Hertz (Hz), where 1 Hz equals 1 cycle per second. In ultrasound, knowing frequency helps you understand image quality because higher frequencies provide better detail (resolution) but don’t penetrate as deeply due to greater attenuation.

The other units measure different quantities: decibels measure a ratio on a logarithmic scale (often used for sound intensity levels), pascals measure pressure, and watts measure power. None of those quantify how often a wave cycles per second, which is why Hertz is the correct unit.