1. (a) Sketch the load characteristics, terminal voltage/load current, of the following types of DC generator: (i) series-connected, (ii) shunt-connected and (iii) compound-connected. (b) State one purpose for which….
Which of the following allows for multiple focal zones and harmonic frequencies?
1.Which of the following allows for multiple focal zones and harmonic frequencies?
b. code excitation
c. dynamic focusing
d. constructive interference
2. Which of the following is a postprocessing feature?
a. cine loop
c. write zoom
d. 3-D acquisition
3. The binary number 0110010 corresponds to a decimal number of:
4. How many shades of gray are in a 6-bit memory?
5. What is the term used to describe a volume picture element?
6. Which of the following modifications would improve this image?
7. Which of the following best describes a digital matrix?
a. storage of picture elements
b. smallest amount of computer memory
c. number of picture elements in a digital image
d. rows and columns of picture elements in a digital image
8. Which of the following improves contrast resolution?
9. Which of the following components increases the number of scan lines?
a. read zoom
d. write zoom
10. Which of the following artifacts improperly displays a true reflector’s location?
a. mirror image
c. focal banding
d. range ambiguity
11. When the Doppler gain setting is too high, which of the following artifacts is most likely to occur?
b. mirror image
c. range ambiguity
d. acoustic speckle
12. Which of the following decreases the likelihood of range ambiguity artifact?
a. perpendicular incidence
b. decreasing the receiver gain
c. decreasing the operating frequency
d. decreasing the pulse repetition frequency
13. The design of ultrasound systems assumes:
a. the thickness of the imaging plane is uniform
b. sound travels at variable speeds in soft tissue
c. sound travels directly to and from a reflector
d. secondary beams travel lateral to the primary beam
43. Weakening of echoes distal to a strongly attenuating structure describes: