Which of the following frequencies is within the audible range?

1. Power is defined as:

 

a. energy between two points

b. rate at which work is performed

c. rate of motion with respect to time

d. amount of force applied to a specific area

2. Animal testing is a form of what type of research?

a. in situ

b. in vivo

c. ex vivo

d. in vitro

3. The intensity of M-mode imaging is greater than the intensity of:

a. color Doppler

b. gray-scale imaging

c. pulsed-wave Doppler

d. continuous-wave Doppler

4. In soft tissue, if the frequency of a wave increases, the propagation speed will:

a. double

b. increase

c. decrease

d. remain the same

5. The range of frequencies found within a pulse describes which of the following terms?

a. duty factor

b. bandwidth

c. harmonics

d. pulse repetition frequency

6. In gray-scale imaging, how many cycles per pulse are generally used?

a. 2 to 3

b. 4 to 5

c. 5 to 10

d. 10 to 30

7. Which of the following frequencies is within the audible range?

a. 15 Hz

b. 15 kHz

c. 25 kHz

d. 25,000 Hz

8. Propagation speed through a medium is determined by the:

a. pulse repetition period

b. intensity and amplitude of the wave

c. density and stiffness of the medium

d. impedance difference between the media

9. Which of the following is an acoustic variable?

a. intensity

b. wavelength

c. particle motion

d. propagation speed

10. In soft tissue, a 7.5-MHz transducer with a two-cycle pulse will generate a spatial pulse length of:

a. 0.2 mm

b. 0.4 mm

c. 0.8 mm

d. 1.5 mm

11. If the stiffness of a medium increases, the propaga­tion speed will:

a. double

b. increase

c. decrease

d. remain the same

 

find the cost of your paper

Sketch the load characteristics, terminal voltage/load current, of the following types of DC generator

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….

what happens if the resistance in series with the shunt field of a DC motor is increased in value

1. Sparking at the trailing edges of the brushes in a DC machine is usually prevented by fitting   (a) copper gauze brushes (b) a compensating winding (c) a compound….

Calculate the synchronous speed of a 10-pole three-phase machine connected to a 50 Hz supply.

1. The generator characteristic shown in Figure 9.28 is for a   (a) shunt machine (b) series machine (c) differentially compounded machine (d) cumulatively compounded machine 2.The speed of a….