Final answer:
Shockwave is not a type of diathermy; diathermy refers to the generation of heat with electromagnetic currents and includes longwave, shortwave, and microwave. Diathermy uses transverse electromagnetic waves, where microwaves fall in the electromagnetic spectrum between infrared and radio waves. Sound waves are longitudinal and mechanical, unlike the transverse electromagnetic waves used in diathermy.
Step-by-step explanation:
The type of diathermy that is NOT included in the list provided is shockwave. Diathermy is a therapeutic treatment that involves the generation of heat in body tissues through high-frequency electromagnetic currents. The options provided, such as longwave, shortwave, and microwave, refer to different ranges of electromagnetic radiation. Electromagnetic waves are transverse waves, which include microwaves, part of the electromagnetic spectrum with wavelengths ranging from 1 millimeter to 1 meter. This is longer than the wavelengths of infrared radiation but shorter than those of radio waves.
When discussing the properties of waves, it is important to note that sound waves are an example of longitudinal waves and require a medium to travel through, unlike electromagnetic waves such as heat (infrared radiation), which do not require a medium and are transverse waves. Microwaves, specifically, are used for heating in microwave ovens and operate at certain frequencies that can efficiently transfer energy to water molecules in food.