Forensics - Chapter 7 Test Review

List and define the two types of lenses in an ordinary microscope.

1) Eyepiece lens - upper lens through which the viewer looks 2) Objective lens - lower lens that is positioned directly over the specimen

What is a condenser?

Condenser - a lens system under the microscope stage that collects the light and focuses it

T or F: The magnification of a microscope with a 10x eyepiece and a 10x objective will be 1,000x

False

T or F: The mechanical system of a microscope is composed of six parts

False

T or F: With the development of the scanning electron microscope, a forensic analyst can now view a particle under a microscope while, at the same time, a beam of light is directed at the particle in order to obtain its absorption spectrum.

False

What is the difference between a monocular and a binocular microscope?

Monocular - one eyepiece Binocular - two eyepieces

Define parfocal

Parfocal - refers to a microscope that will remain in focus when an image is focused with one objective, and another objective is rotated into place

T or F: The stereoscopic microscope is the most frequently used and versatile microscope found in the crime lab

True

What type of microscope would a forensic scientist most likely use in each of the following situations?

What type of microscope would a forensic scientist most likely use in each of the following situations?

Which microscope can be used to determine whether a suspect has recently fired a gun?

a scanning electron microscope

The major attractions of the scanning electron microscope (SEM) include all of the following except: a) its high magnification b) its ability to polarize light c) its high resolution d) its great depth of focus

b) its ability to polarize light

Which of the following is not a part of the mechanical system of a compound microscope? a) coarse adjustment b) objective lens c) body tube d) stage

b) objective lens

examining two bullets to see if they were fired by the same gun

comparison microscope

How does one determine the total magnification of a compound microscope?

eyepiece X objective = total magnification

determining the chemical composition of paint chips

microspectrophotometer microscope

identifying birefringent minerals present in soil

polarizing microscope

examining extremely tiny specimens that require very high magnification

scanning electron microscope (SEM)

examining a large specimen, such as a tool or piece of clothing

stereoscope microscope

Which microscope is the most frequently used and versatile microscope found in the crime lab?

the stereoscopic microscope