Physics 2 Test chapters 16 &17

Question 1

What is the harmonic frequency given the fundamental frequency?

Answer 1

double

probe frequency = 4.5MHz then Harmonics frequency = 9MHz

pg 269

Question 2

What is the fundamental frequency given the harmonic frequency?

Answer 2

1/2

Question 3

When are harmonics created?

Answer 3

when the sound is reflected at 2x the frequency of the transmitted sound.
pg 269
during transmission in tissue
pg 283

Question 4

What kind of behavior is need for harmonics

Answer 4

nonlinear

Question 5

What is dynamic range?

Answer 5

A method of describing the extend of which a signal can vary and still maintain accuracy.
page 266

Question 6

What does compression do to dynamic range?

Answer 6

reduces the dynamic range of a signal without introducing errors.

• largest signal remains the largest
• smallest remains the smallest
• the range of signals is reduced

pg 266

Question 7

When are contrast harmonics created?

Answer 7

• during reflection as energy is converted from the fundamental frq to the harmonic frq.
• created because microbubble act in a nonlinear manner when struck by sound waves

pg 278

Question 8

When are tissue harmonics created?

Answer 8

As sound travels through the body a small amount of energy is converted from the fund frq to harmonic frequency, the result is tissue harmonics
pg 272

Question 9

The MI if you have a high index or a low index and what it means in terms of harmonics (4 questions pertaining to this)

Answer 9

charts on pages 280 and 281

Question 10

pulse inversion harmonics

Answer 10

• imaging technique designed to utilize harmonic reflections , while eliminating distorted fundamental reflections.
• 2 consecutive pulses,one positive and one negative, are transmitted down each scan line

Question 11

When the bubbles expand, will they expand with a low MI or a high MI?

Answer 11

high

pg. 281