Cellular telephones operate at frequencies of about 1,000 megahertz (1 gigahertz).
Ultrasound machines use sound waves at frequencies of 1 million to 20 million hertz, or cycles per second, far above the audible range.
(The same is true for some mobile-phone signals, which are transmitted at frequencies of 700MHz-3.5GHz).
Quartz crystals oscillating at frequencies of 100,000 hertz can be compared and frequency differences determined to an accuracy of one part in 1010.
Loran-C transmitters operate at frequencies of 90 to 110 kilohertz, and the signals are useful at distances of 1,800 nautical miles or more.
At frequencies of 10 KHz, 100 kHz and 1 MHz.
The platform was displaced horizontally in an anteroposterior direction at frequencies of 0.2 or 0.6Hz.
The attenuation for the three materials was found at frequencies of 315 Hz and 400 Hz.
The measurement was done at frequencies of 1, 50, and 100 kHz.
Deposition was performed in stationary- and pulsed-current conditions at frequencies of 1 to 10 kHz.
The samples sintered at 950°C were measured at frequencies of 1, 10, and 100 kHz.
