chap 9 determining focal depth purple questions

A pair of 6 MHz probes are identical except for the active element diameter. The active element diameter are 6 mm and 10 mm, respectively. The sound beam of which probe will have a shallower focus?

The probe with a 6 mm active element has a shallower focus. Smaller diameter crystals produce beams with shallow or foci.

A pair of 9mm diameter probes are identical except for frequency, which is 3 MHz and 6 MHz, respectively. Which beam will have a shallower focus?

The 3 MHz has a shallower Focus. Focal depth increases with increasing frequency. The beam created by the 6 MHz probe has a deeper focus.

Which of the following probes creates a beam with the deepest focus?

A. 4 mm diameter, 4 MHz

B. 6 mm diameter, 8 MHz

C. 6 mm diameter, 2 MHZ

D. 5 mm diameter, 8 MHz

B. Longer focal lengths are associated with large diameter, high frequency probes. The probe identified as choice B has the largest diameter and highest frequency and, therefore, the deepest focus.

Which of the following probes creates a beam with the shallowest focus?

A. 4 mm diameter, 4 MHZ

B. 6 mm diameter, 8 MHz

C. 4 mm diameter, 2 MHz

D. 5mm diameter, 8 MHz

C. Shorter focal lengths are associated with small diameter, low frequency probes. The probe identified as choice C has the smallest diameter and lowest frequency and, therefore, the shallowest focus.

Which of the following probes creates a beam with the shallowest focus?

A. small diameter, high frequency

B. large diameter, high frequency

C. small diameter, low frequency

D. large diameter, low frequency

C. Shorter focal lengths are associated with small diameter, low frequency probes.

True or False. Active element diameter and near zone length are directly related.

True. Diameter and near zone length are directly related.

True or False. Transducer frequency and near zone length are inversely related.

False. Frequency and near zone length are directly related.

True or False. Wavelength and near zone length are inversely related.

True. Wavelength and near zone length are inversely related.