Answer #44

The correct answer is A. The beam will be refracted away from a perpendicular line to the interface between the media. Since medium 2 has a faster propagation velocity for ultrasound it will be refracted away from the midline as shown in the figure below [insert refraction low to high velocity medium]. This is based on Snells' law that relates the sine of the angle of incidence and refraction to the velocity of travel through the two mediums. The higher the velocity the greater the angle of refraction. The other choices are therefore not correct.