SPI PRACTICE questions exam 1 with
correct answers 2024
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 the following has the greatest effect on the focal length of a single element
transducer? -answer- ✔Doubling the element diameter
Spatial pulse length is the product of the number of cycles in the pulse and the -answer-
✔wavelength
Manipulating the output power control of an ultrasound instrument does NOT affect the -
answer- ✔pulse repetition frequency
What will be affected by the power? -answer- ✔echo amplitude
beam intensity
acoustic exposure to the patient
display dot brightness
On pulse-echo equipment, the transducer actually transmits -answer- ✔under 1% of the
time
Ultrasonic intensity is measured in units of -answer- ✔energy per unit time per unit area
(Watt)
watt= -answer- ✔joules/second
What fraction of ultrasonic energy is typically reflected at soft tissue interfaces? -
answer- ✔1%
If the reflected signal intensity from Object 1 is ten times greater than Object 2, what is
the dB difference in reflected intensity between Object 1 and Object 2? -answer- ✔10
dB
SPI PRACTICE questions exam 1