Exam
Question 1
A micrometer is defined as:
A. 10^-3
B. 10^-6
C. 10^-9
D. 10^-12
A nanometer is defined as:
A. 10^-3
B. 10^-6
C. 10^-9
D. 10^-12
Define the measurements micrometer and nanometer.
Micrometer is defined as
10^-6 m Nanometer is
defined as 10^-9 m
Question 2:
Resolution and contrast are two critical factors that influence
your ability to see an object. Explain each.
Resolution is how far apart two things can be and
still be seen as separate objects. If the resolution
is poor or low, then two objects might look like just
one.
Contrast, on the other hand, is about the difference
in how much light is absorbed between two objects.
When contrast is low, the background looks really
bright, making it hard to see multiple objects
clearly.
For example, it’s like trying to see two dark objects
in the dark (low contrast) versus seeing those same
objects in bright daylight (high contrast).
What are the two critical factors that influence your ability to
see an object?
Resolution
Contrast
, BIOD 171 Module 3
Exam
Question 3
Assuming a constant (non-adjustable) light source power, identify
the part of the microscope you would adjust to limit the amount of
light entering the microscope.
A. Eye piece
B. Objective
C. Condenser
D. Iris diaphragm
Assuming a fixed ocular, identify the part of the microscope you
would adjust to enhance the magnification of a sample.
A. Eye piece
B. Iris diaphragm
C. Objective
D. Condenser
If you wish to increase the amount of light going into a
microscope, what part you adjust?
Iris diaphragm
Question 4
What is the total magnification (relative to your eye) of a sample
imaged with a 20x objective and a 15x eyepiece? Show your math.
20 x 15 = 300x magnification
What is the total magnification (relative to your eye) of a sample
imaged with a 40x objective and a 10x eyepiece? Show your math.
40 x 10 = 400x magnification
What is the total magnification (relative to your eye) of a sample
imaged with a 60x objective and a 10x eyepiece? Show your math.
60 x 10 = 600x magnification
How is the total magnification of an object calculated?
Total magnification = ocular lens magnification x
objective lens magnification