Which of the following numbers is not listed as a diathermy frequency?

Which of the following numbers is not listed as a diathermy frequency?

• A. 11.11
• B. 13.56
• C. 27.17
• D. 40.68

Answer: (A)

Diathermy uses radiofrequency energy to heat tissues, and the frequencies used for medical diathermy are fixed to specific MHz values to fit safety and regulatory guidelines. The common therapeutic shortwave diathermy frequencies are 13.56 MHz, 27.12 MHz, and 40.68 MHz. Because 11.11 MHz is not part of that standard set, it isn’t listed as a diathermy frequency. The other numbers given—13.56 and 40.68 MHz—are examples of standard frequencies used in practice, while a value like 27.17 MHz would be close to the standard 27.12 MHz but is not the exact commonly cited frequency. The key idea is that diathermy relies on a small, defined range of frequencies rather than a broad spread, so anything outside those recognized bands isn’t considered a listed diathermy frequency.

Diathermy uses radiofrequency energy to heat tissues, and the frequencies used for medical diathermy are fixed to specific MHz values to fit safety and regulatory guidelines. The common therapeutic shortwave diathermy frequencies are 13.56 MHz, 27.12 MHz, and 40.68 MHz. Because 11.11 MHz is not part of that standard set, it isn’t listed as a diathermy frequency. The other numbers given—13.56 and 40.68 MHz—are examples of standard frequencies used in practice, while a value like 27.17 MHz would be close to the standard 27.12 MHz but is not the exact commonly cited frequency. The key idea is that diathermy relies on a small, defined range of frequencies rather than a broad spread, so anything outside those recognized bands isn’t considered a listed diathermy frequency.