Free Ultrasound Physics Test Questions - Test Prep Review Nov 26, 2018Increases Decreases Increases Decreases 10,000 20,000 30,000 40,000 Pressure and particle velocity are in-phase. Particles in the medium oscillate with equal Ultrasound Physics _SPI_ Mock Exam Questions - Quizlet Ultrasound Physics _SPI_ Mock Exam Questions. A sonographer is scanning a patient with a 3 MHz probe and replaces it with a 6 MHz probe. All of the following statements are FALSE, except: a. The 6 MHz beam will travel at a lower speed than the 3 MHz beam b. The 6 MHz beam will travel faster than the 3 MHz beam c.