Reflected impedance - Study guides, Class notes & Summaries

The impedance of a medium iscorrect answerEqual to density x propagation speed the ratio of particle pressure to particle velocity within the imaging field iscorrect answerimpedance Which of the following produces the least resistance to the transmission of the beam?correct answerblood An example of a nonspecular reflector iscorrect answerliver tissue At an interface of 0.25 Rayls and 0.75 rays, what percentage of intensity is reflected?correct answer25% (answer uses the reflection c...

The doppler shift is 5000 Hz. The pulse repetition frequency is 9000 Hz. Which of the following is true? A. peak pressure gradient is 36mmHg B. range ambiguity will occur C. aliasing will occur D. the peak velocity is equal to 2 m/s - ️️C. aliasing will occur When evaluating a suspected arterial stenosis, a doppler angel of ____ degrees will produce the most accurate flow velocity. A. 0 B. 30 C. 60 D. 90 - ️️A. 0 Spatial resolution is: A. the minimum reflector separation req...

What best describes a sound wave? -answer- A mechanical longitudinal wave What MUST be different on the two sides of an interface for refraction to occur? -answer- Propagation speed of sound and oblique incidence The characteristic acoustic impedance of a medium equals the product of -answer- density and speed of sound Ultrasonic attenuation is considered to consist of two parts scattering and absorption. Absorption is -answer- local conversion of ultrasound energy to heat Which of t...

What are three principle characteristics that define an AC waveform? Answer The three principle characteristics that define an AC waveform are: (1) frequency; (2) wavelength; and (3) amplitude. What is one of the basic principles of resistance reflected in the familiar practices of grounding and bonding? Answer Grounding and bonding practices reflect the basic principle that electricity always follows the path of least resistance. What comprises the impedance of a coaxial cable or a device...

what word describes the bending of an RF signal as it passes through a medium of a varying density from that of free space Refraction Q. What can cause an excessively high VSWR (voltage standing wave ratio)in a WLAN RF transmission line? An impedance mismatch in the RF cables and connectors Q. What factors influence the distance that an RF signal can be effectively received? *Receiving station's radio sensitivity *Free Space Path Loss *Transmitting station's output power ...

What does an Audiologist do? - • Prevention of hearing loss (monitoring school/industries programs) • Identification of hearing loss (screening) • Evaluations (hearing and balance assessments) o Balance = vestibular system (semicircular canals) • Selecting and dispensing hearing aids • Habilitation & rehabilitation of H impaired (90% of the job) o Habilitation is educating/counseling those who are born deaf o Rehabilitation is educating/counseling those who became deaf Among ...

▪ Newton's law of gravitation - Ansthe fore between two-point masses is directly proportional to the product of the masses and inversely proportional to the square of the separation of the distance between them F=(-GMm)/r^2 ▪ Brownian motion - Ansthe continuous random motion of small particles suspended in a fluid, visible under a microscope ▪ Absolute scale of temperature - AnsA scale for measuring temperature based on absolute zero and the triple point of pure water, with grad...

ATT Test 10 Radars What is an echo - Rf energy reflected from an object What four types of energy does an echo provide? - bearing, range, elevation, velocity What is length of line (LOS) known as? - range What is the most commonly used reference level in the decibel system for radar? - 1mW To be separately distinguishable by the radar system, two objects that must be separated by how many beam widths? - atleast one beam width What is the greatest limiting factor of a receivers...

ATT Week 11 Test (FC) What causes refraction? - A change in the speed of light. What is the most common optical detector? - Photo Diodes. __________ determines the color of light. - Wavelength What affects a detectors responsivity? - Changes in wavelength. The range of frequency that an optical fiber cable has is known as___________. - Bandwidth What optical fiber cable is made of several concentric layers? - Multimode graded-index What is a superheterodyne good for? - Extre...