Question 1: Define ultrasound and explain how it differs from sounds audible to humans.

Answer: Ultrasound refers to sound waves with frequencies above 20,000 Hz, which are inaudible to humans, unlike audible sound waves which have frequencies between 20 Hz and 20,000 Hz.

Question 2: Describe how ultrasound waves are produced and detected in medical imaging.

Answer: Ultrasound waves are produced by a piezoelectric crystal that vibrates when an electric current is applied. These waves travel through the body and are reflected back to a detector, creating images based on the echoes received.

Question 3: Explain why ultrasound is useful in medical diagnostics.

Answer: Ultrasound is useful because it can penetrate body tissues to produce real-time images of internal organs without using harmful radiation.

Question 1: An ultrasound wave has a frequency of 5 MHz. Calculate its wavelength in soft tissue where the speed of sound is approximately 1540 m/s. (Use the formula: wavelength = speed / frequency).

Answer: Wavelength = 1540 m/s ÷ 5,000,000 Hz = 0.000308 m or 0.308 mm

Question 2: If an ultrasound device emits waves at 2 MHz with a wavelength of 0.77 mm, verify the speed of sound in the medium using the formula: speed = wavelength × frequency.

Answer: Speed = 0.00077 m × 2,000,000 Hz = 1540 m/s

Question 1: Describe a simple experiment to demonstrate how ultrasound waves reflect at boundaries between different materials.

Answer: Use an ultrasound transducer to send waves into different materials (e.g., plastic, metal, water). Measure the time it takes for echoes to return when waves reflect at boundaries between materials, illustrating reflection and the importance of impedance differences.

Question 2: List three safety precautions to consider when working with ultrasound equipment in a laboratory setting.

Answer: Ensure proper shielding to prevent exposure to high-frequency waves, avoid prolonged direct contact with ultrasound transducers, and follow manufacturer guidelines for safe operation.

Question 1: A patient’s ultrasound scan detects echoes returning at different times, indicating varying distances of internal organs. If an echo returns after 0.002 seconds in soft tissue (speed of sound = 1540 m/s), estimate the distance to the internal structure.

Answer: Distance = (Speed × Time) / 2 = (1540 m/s × 0.002 s) / 2 = 1.54 meters / 2 = 0.77 meters

Question 1: Explain how ultrasound technology is used in industry or other fields besides medicine.

Answer: Ultrasound is used in industrial non-destructive testing to detect flaws in materials like metals and plastics, in cleaning delicate objects, and in sonar systems for underwater navigation.

Question 2: Identify one advantage and one limitation of using ultrasound for medical imaging.

Answer: Advantage: It provides real-time images without harmful radiation. Limitation: It has limited ability to image structures deep inside the body or through bones.