Doppler effect results from change in-: (A) Amplitude of sound, (B) Frequency of sound, (C) Direction of sound, (D) None of the above
Answer is B. Doppler effect: change in frequency because of relative motion between moving source of sound and observer. Example: Sound waves hitting resting parenchyma Sound wave hitting moving RBC The difference gives color coding doppler effect. Color coding: based on direction of flow Flow TOWARDS probe: RED Flow AWAYfrom probe:BLUE Color does NOT depend on aery or vein Intensity of color depends on velocity of flow