Question

What kind of ultrasound is produced by piezoelectric crystal?

• A. ( \text{Pressure wave ultrasound} ) \
• B. ( \text{Electrical wave ultrasound} ) \
• C. ( \text{Sound wave ultrasound} ) \
• D. ( \text{Simple ultrasound} ) \

Hint:

Remember that sound waves, including ultrasound, are mechanical waves. They propagate through a medium by causing particles of the medium to oscillate, creating regions of compression (high pressure) and rarefaction (low pressure). Hence, they are fundamentally pressure waves.

Answer 1

The Correct Option is A

Ultrasound, by definition, refers to sound waves with frequencies higher than the upper audible limit of human hearing.
A piezoelectric crystal is the core component of an ultrasound transducer.
It exhibits the piezoelectric effect, meaning it can convert electrical energy into mechanical energy (sound waves) and vice-versa.
When an alternating electric voltage is applied across a piezoelectric crystal, it vibrates at a high frequency, generating mechanical vibrations that propagate as sound waves.
These sound waves are longitudinal waves, meaning they consist of compressions and rarefactions of the medium, which are essentially pressure variations.
Therefore, the ultrasound produced by a piezoelectric crystal is a pressure wave ultrasound.
While it is a type of sound wave, "pressure wave" more accurately describes its physical nature in the context of its propagation through tissue for imaging.
Electrical wave ultrasound is incorrect as ultrasound is a mechanical wave, not electrical.
"Simple ultrasound" is not a specific type.