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41 Multiple Choice Antworten
- Human ear shows the highest sensitivity for sounds characterized by:
a) Homogeneous timbre
b) Frequency between 10 – 20000 HZ
c) Frequency of approximately 1000 Hz
d) Frequency of approximately 3000 Hz
e) Frequency of approximately 10000 Hz
- Blood velocity in the vessels can be estimated when applying:
a) fMRI
b) Infrared waves
c) Measurements of pulse frequency at different sites
d) Calculations of the acoustic resistances
e) Doppler effect
- Indicate proper statement regarding X and gamma rays
a) gamma rays are corpuscular and X rays are electromagnetic
b) gamma rays are electromagnetic and X rays are corpuscular
c) gamma and X-rays are both corpuscular but consist of different elementary particles
d) gamma and X-rays have both electromagnetic nature
e) gamma and X rays have the same frequency spectrum
- The feature that a lens focuses the light not at a focal point but at a blurred spot is referred to as:
a) chromatic aberration
b) spherical aberration
c) astigmatism
d) diffraction
e) refraction
- Typically, the wavelength of absorbed photon is:
a) Longer than that of the emitted one
b) Equal to that of the emitted one
c) Shorter than that of the emitted one
d) Is shortened due to radiationless transitions
e) Equal to the Larmor’s precession frequency
- The energy of interaction between the magnetic moment and the external magnetic field is minimal when:
a) Magnetic moment and magnetic field are antiparallel
b) Magnetic moment and magnetic field are parallel
c) Magnetic moment and magnetic field are perpendicular
d) The angle between magnetic moment and magnetic field is 135 degrees
e) The energy of interaction does not depend on the angles between these quantities
- In the MRI scanning, the gradients of magnetic field are used to:
a) Enhance the intensity of the signal
b) Facilitate the phenomenon of magnetic resonance
c) To get rid of radiationless transitions in the nuclei
d) To enable examination of a defined tiny part (slice) of the patient’s body
e) To facilitate the T2 relaxation time
- Indicate in which units is measured the ECG signal:
a) Volts/time
b) Ampers/time
c) Volts
d) Ampers
e) Tesla
