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Note: Some material based on books have
quoted passages.
This quiz is based on the information presented
in Handbook of Dielectric and Thermal Properties of Materials at Microwave Frequencies,
by Theodore Anderson. This book is a wealth of information of dielectric characteristics
of biological tissues in plants, animals, as well as for ceramics, soils and minerals.
Particular attention is paid to properties in the ISM frequency bands. Extensive
sources for similar studies are provided.
Also consider: USAFSAM-TR-85-73,
Radiofrequency Radiation Dosimetry Handbook (4th
Edition)
This is the mother of all such references for SAR studies.
1. What is a serious reason for uneven distribution of
the thermal field in lossy media?
a) Lossiness b) Temperature gradients c) Thermal runaway
d) Impurities
2. What is the mechanism for generating heat in dielectric
materials via microwaves?
a) Dipole polarization where polar molecules try to align themselves with
the applied field b) High internal friction c) High temperature
gradients d) Atomic molecularity
3. What name is given to a resonant cavity method for measuring
complex dielectric permittivity of lossy materials?
a) Spatial injection method b) Surface current method c)
Skin effect method d) Perturbation method
4. What does heat capacity of a material measure?
a) Ability to accumulate heat by increasing its temperature b)
Amount of heat contained c) Absolute temperature d) Relative temperature
5. What are the main mechanisms for interaction between
EM waves and biological (e.g., brain) tissue?
a) Oscillation of polar water molecules and ions b) Radiation
of conductive salts c) Conduction of mineral impurities d) All
the above
6. Which list represents materials ordered from least
to most polar high frequency dielectric properties.a) PVC, rubber, polyethylene
b) Rubber, PVC, polyethylene c) Polyethylene, rubber, PVC d)
All have equal polar properties at high frequency
7. Which property is very important in affecting temperature
distribution in liquids heated by microwaves?
a) Density b) Conductivity c) Dielectric constant
d) Viscosity
8. Which body component has the highest conductivity in
the 915 MHz ISM band?
a) Cerebrospinal fluid b) Brain c) Bone marrow d)
Tongue
9. Which body component has the lowest conductivity in
the 915 MHz ISM band?
a) Blood b) Brain c) Bone marrow d) Tongue
10. What typically happens to conductivity of body tissues
as frequency across the ISM bands is increased?
a) Increases b) Decreases c) Does not change d)
Initially increases, then decreases
Need some help? Click here for
the
answers and explanations.
Posted August 21, 2019
(original 8/9/2012)
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