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 instrument properly locates each series of reflectors in individual scan lines for storage?
1. Which of the following changes will improve this spectral display?
a. decrease the wall filter; decrease the Doppler gain
b. move baseline up; decrease the pulse repetition frequency
c. decrease the focal zone; decrease the pulse repetition frequency
d. decrease the wall filter; decrease the pulse repetition frequency ,2. Which of the following determines the number of scan lines per frame?
a. contrast resolution
b. operating frequency
c. temporal resolution
d. pulse repetition frequency
3. When coursing from a medium of lower propagation speed to a medium of higher propagation speed, the frequency of the sound wave will:
d. remain constant
4. Flow reversal in diastole indicates:
a. a stenosis
b. an obstruction
c. high resistance distally
d. high resistance proximally
5. How can the sonographer increase the temporal resolution of this sonogram?
a. increase beam width
b. decrease imaging depth
c. increase transducer frequency
d. decrease the number of focal zones
6. How wide are the elements of a linear phased-array transducer?
a. one wavelength
b. one half wavelength
c. one tenth wavelength
d. one quarter wavelength
7. In a time-gain compensation curve, the delay represents:
a. area of minimum amplification
b. area of maximum amplification
c. available region for depth compensation
d. depth at which variable compensation begins
8. Which instrument properly locates each series of reflectors in individual scan lines for storage?
a. scan converter
c. fast Fourier transfer
d. random access memory
9. Specular reflections occur when the sound wave:
a. strikes a rough surface
b. encounters a strong reflector
c. encounters a smaller reflector
d. strikes a smooth, large reflector