4 — Geometrical optics, microscopy, electron microscopy

Question 1

Define the index of refraction.

Answer 1

Question 2

Write Snell’s law of refraction.

Answer 2

Question 3

What is the shortest resolvable distance in a light microscope?

Answer 3

Question 4

How can the resolving power of a microscope be increased?

Answer 4

Question 5

What is numerical aperture?

Answer 5

Question 6

Give the formula for the resolving power (f) of a conventional light microscope.

Answer 6

Question 7

What is the function of the dichroic mirror in a fluorescence microscope?

Answer 7

Question 8

What is the function of the excitation filter in a fluorescence microscope?

Answer 8

Question 9

What is the function of the emission filter in a fluorescence microscope?

Answer 9

Question 10

List at least three of the imaging aberrations in optical systems

Answer 10

Question 11

Give the equation for the relationship between the image distance (i), object distance (o) and the focal distance (f).

Answer 11

Question 12

Give the definition and SI unit of diopter

Answer 12

Question 13

What were those two discoveries that made construction of an electron microscope possible?

Answer 13

Question 14

List at least three signals that can be detected during an electron microscopic measurement

Answer 14

Question 15

What are the two types of electron microscopes?

Answer 15

Question 16

What is the principle of transmission electron microscopy?

Answer 16

Question 17

What is the principle of scanning electron microscopy?

Answer 17