WorksheetsForensic Science Chapter 6 Test - Fibers
Total questions: 40
Worksheet time: 20mins
Fiber evidence can have probative value.
True
False
It is easy to identify synthetic fibers because they have aperfectly round cross section.
True
False
A piece of fabric can be individualized to a particular garment.
True
False
A fiber can be individualized to a particular piece of fabric.
True
False
Fibers make up fabrics.
True
False
Silk is a synthetic fiber.
True
False
The most common type of natural fiber is wool.
True
False
The most common type of synthetic fiber is denim.
True
False
An investigator can use the way a fabric accepts a particular dye to identify and compare samples.
True
False
Optical microscopy is one of the most important methods of fiber identification.
True
False
An electropherogram is a record of chromatographic separation.
True
False
A gray cotton fiber was found on the red sweater of a victim. A gray cotton fiber was taken from a suspect's sweatshirt. After testing 280 gray sweatshirts, the lab found the fiber matched 28 of them. What is the probability that the crime scene fiber and that of the suspect matched simply by chance?
one in 28
one in 10
one in 280
cannot be calculated by this information
Some examples of natural fibers are:
jute, rayon, silk and wool
wood, cotton, cashmere
linen, cotton, acetate, rayon
linen, cotton, wool, Dacron
Fibers that are polymers are:
natural
synthetic
all fibers are polymers
no fibers are polymers
To test the dye in a particular fiber, it can be extracted and then tested using
a burn test
a thermal decomposition test
chemical tests
any of these
Linen is classified as a
natural fiber
synthetic fiber
regenerated fiber
animal fiber
Out of seven analytical tests performed to match a questioned fiber to a known, you find one discrepancy. The cross-section is triangular rather than round. What do you do?
don't worry about it; six out of seven is good evidence
report that there is no association between the questioned fiber and the known
assume that the one test was wrong
only testify about the six tests that matched
The first truly synthetic fiber to be discovered and sold was
polyester
cotton
nylon
acrylic
Which of the following will fluoresce under ultraviolet light?
polyester
cotton
nylon
acrylic
The Amanda Davies case showed the importance of
fiber evidence
statistical information
identifying particular fabrics
none of these
Which of the following can be used to analyze fibers?
Fourier Transform Infrared (FTIR)
Optical Microscopy
Pyrolysis gas chromatography
all of these
none of these
Which of the following properties should be examined when comparing two fibers?
birefringence
diameter
color
all of these
Which of the following fibers DO NOT come from an animal source?
asbestos
mohair
silk
wool
cashmere
Fibers that are made by plants or animals are called
natural
plain
synthetic
real
Wool, when burned, smells like
tar
burning hair
vinegar
diesel fuel
Usually made up of many filaments twisted or bonded together
fabric
fiber
filament
blend
The lengthwise yarn
elute
twill
warp
weft
to extract one material from another
blend
elude
satin
twill
ratio used to characterize and compare components in liquid chromatography
chromatography
chromagram
viscosity
retention factor
A method of separating components of mixtures
chromatography
chromagram
viscosity
density
the crosswise yarn
blend
twill
warp
weft
a single strand of material
filament
fiber
fabric
twill
mass divided by volume
retention factor
viscosity
density
Becke Line
a halo-like shadow around an object immersed in a liquid of a different refractive index
retention factor
Becke Line
viscosity
density
a diagonal weave pattern; denim is an example
blend
twill
polymer
satin
simplest and most common weave pattern
blend
satin
twill
plain
a fabric made up of two or more different types of fiber
blend
fabric
twill
yarn
a cloth material made up of fibers woven or bonded together
yarn
filament
fabric
twill
man-made
polymer
synthetic
twill
satin
resistance to flow
viscosity
retention factor
Becke Line
chromatogram
