Question 1

Degree of scattering in transmission electron microscope is a function of                      
A)wavelength of electron beam used
B)number of atoms that lie in the electron path
C)number and mass of atoms that lie in the electron path
D)mass of atoms that lie in the electron path

Accepted Answer

The degree of scattering in a transmission electron microscope (TEM) is influenced by both the number and mass of atoms that lie in the electron path. This is because the interaction between the electron beam and the sample depends on how many atoms are encountered (which affects the probability of interactions) and the mass of these atoms (which influences the scattering cross-section).

Question 2

Negative Staining is used for examining
A)virus particles
B)protein molecules
C)bacterial flagella
D)virus particles, protein molecules and bacterial flagella

Accepted Answer

Negative staining is a versatile technique used in microscopy to visualize tiny particles such as virus particles, protein molecules, and bacterial flagella, which are otherwise difficult to see against a complex background. This method stains the background, leaving the particles unstained for contrast.

Question 3

Which among the following helps us in getting a three-dimensional picture of the specimen?
A)transmission electron microscope
B)scanning electron microscope
C)compound microscope
D)simple microscope

Accepted Answer

Scanning electron microscopes (SEMs) provide three-dimensional images of specimens by scanning the surface with a focused beam of electrons. This contrasts with transmission electron microscopes (TEMs), which offer two-dimensional, highly magnified images by transmitting electrons through the specimen. Compound and simple microscopes use visible light and magnifying lenses, producing two-dimensional images.

Question 4

The secondary electrons radiated back in scanning microscope is collected by?
A)specimen
B)anode
C)vacuum chamber
D)cathode

Accepted Answer

The secondary electrons radiated back in a scanning electron microscope are collected by the anode. The anode is designed to attract and collect these electrons to generate the image.

Question 5

On what factors do the intensity of secondary electrons depend upon?
A)shape of the irradiated object
B)chemical composition of the irradiated object
C)number of electrons ejected
D)size and chemical composition of the irradiated object, number of electrons ejected and on the number of electrons reabsorbed by surrounding

Accepted Answer

The intensity of secondary electrons depends on multiple factors including the size and chemical composition of the irradiated object, the number of electrons ejected, and the number of electrons reabsorbed by the surroundings. These factors collectively influence the overall intensity of secondary electrons emitted from a material upon irradiation.

Question 6

The resolution attainable with standard TEM is less than the theoretical value.

Accepted Answer

The resolution attainable with standard Transmission Electron Microscopy (TEM) is often less than the theoretical limit due to practical limitations such as lens aberrations and instabilities in the electron beam and the specimen.

Question 7

Which of the following component of TEM focuses the beam of electrons on the sample?
A)ocular lens
B)condenser lens
C)stage
D)column

Accepted Answer

The condenser lens in a Transmission Electron Microscope (TEM) is responsible for focusing the electron beam onto the sample. This is crucial for achieving the desired resolution and magnification.

Question 8

Image formation in electron microscope is based on                                                         
A)column length
B)electron number
C)differential scattering
D)specimen size

Accepted Answer

Differential scattering of electrons by the specimen creates variations in electron intensity, which is used to form images in an electron microscope.

Question 9

The biological materials have little intrinsic capability to                                           
A)scatter electrons
B)stain
C)remain viable
D)be captured

Accepted Answer

Biological materials have little intrinsic capability to scatter electrons, which is why electron microscopy often requires staining to enhance contrast.

Question 10

Glutaraldehyde is a                                  
A)metal
B)fixative
C)non-metal
D)atomic species

Accepted Answer

Glutaraldehyde is widely used as a fixative for biological tissues, preserving them for examination under a microscope by cross-linking proteins.

Question 11

Osmium is a                                         
A)non metal
B)heavy metal
C)alloy
D)light metal

Accepted Answer

Osmium is a heavy metal, known for being one of the densest elements that exists.

Question 12

In TEM, the tissue is stained by floating on drops of                                               
A)hydrocarbons
B)slow-molecular weight stains
C)heavy metal soutions
D)oil immersion

Accepted Answer

In Transmission Electron Microscopy (TEM), tissues are stained with heavy metal solutions, such as lead or uranium, to increase electron density and contrast, allowing for detailed visualization of cellular structures.

Question 13

Shadow casting is a technique of visualizing
A)isolated particles
B)mounts
C)shoot tips
D)root tips

Accepted Answer

Shadow casting is a technique used in microscopy to enhance the visibility of small and isolated particles, such as viruses or nanoparticles, by casting a shadow with a directed light source or electron beam, making them easier to observe and analyze.

Question 14

Surface is usually more than----------atomic layer deep and is a region of ---------- atomic potentials.
A)one, uniform
B)one, non-uniform
C)two, uniform
D)two, non-uniform

Accepted Answer

The surface of a material typically extends more than one atomic layer deep and is characterized by non-uniform atomic potentials due to the different environment experienced by surface atoms compared to those in the bulk.

Question 15

Surface analysis can provide information that classic methods like microscopic cannot.

Accepted Answer

Surface analysis techniques, such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM), can provide detailed information about the surface composition, chemical states, and topography at the nanoscale level, which traditional optical microscopy cannot due to its limited resolution and surface sensitivity.

Question 16

In surface spectrometer, which of the following beam is analysed?
A)reflected beam
B)absorbed beam
C)refracted beam
D)incident beam

Accepted Answer

In surface spectrometry, the reflected beam is analyzed to determine the properties of the surface being studied. This technique relies on measuring the intensity and characteristics of light that is reflected off the surface of a material.

Question 17

Which of the following is a type of electron spectroscopy?
A)mikes
B)auger spectroscopy
C)secondary ion mass spectroscopy
D)ion scattering spectroscopy

Accepted Answer

Auger spectroscopy is a type of electron spectroscopy used to analyze surfaces by detecting the energy of electrons emitted from the surface.

Question 18

Surface analysis cannot provide any chemical information directly.

Accepted Answer

Surface analysis techniques, such as X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), can directly provide chemical information about the composition and chemical states of elements on the surface of a material.

Question 19

Which of the following is also known as X- ray photoelectron spectroscopy?
A)auger electron spectroscopy
B)electron impact spectroscopy
C)electron spectroscopy for chemical analysis
D)secondary ion mass spectroscopy

Accepted Answer

Electron Spectroscopy for Chemical Analysis (ESCA) is another name for X-ray Photoelectron Spectroscopy (XPS), which is a technique used to analyze the surface chemistry of materials by measuring the kinetic energy and number of electrons that escape from the top 1 to 10 nm of the material being analyzed.

Question 20

Which of the following methods utilizes the emission of low energy electrons in a process?
A)auger electron spectroscopy
B)electron impact spectroscopy
C)electron spectroscopy for chemical analysis
D)secondary ion mass spectroscopy

Accepted Answer

Auger electron spectroscopy utilizes the emission of low energy electrons following the relaxation of an atom after ionization, making it the correct choice.

Quiz 8: Electron Microscopy, Surface Analysis, and Transdermal Drug Delivery

Degree of scattering in transmission electron microscope is a function of

Negative Staining is used for examining

Which among the following helps us in getting a three-dimensional picture of the specimen?

The secondary electrons radiated back in scanning microscope is collected by?

On what factors do the intensity of secondary electrons depend upon?

The resolution attainable with standard TEM is less than the theoretical value.

Which of the following component of TEM focuses the beam of electrons on the sample?

Image formation in electron microscope is based on

The biological materials have little intrinsic capability to

Glutaraldehyde is a

Osmium is a

In TEM, the tissue is stained by floating on drops of

Shadow casting is a technique of visualizing

Surface is usually more than----------atomic layer deep and is a region of ---------- atomic potentials.

Surface analysis can provide information that classic methods like microscopic cannot.

In surface spectrometer, which of the following beam is analysed?

Which of the following is a type of electron spectroscopy?

Surface analysis cannot provide any chemical information directly.

Which of the following is also known as X- ray photoelectron spectroscopy?

Which of the following methods utilizes the emission of low energy electrons in a process?