Question 1
An X – ray having a wavelength of 1.67 x 10-10 undergoes the first-order reflection. What is the glancing angle (θ) if the spacing between the two planes is 6 x 10-10?
A. 6.25°
B. 8.99°
C. 7°
D. 8°
View Answer
Question 2
Find the odd one out.
A. Fluoroscopy
B. Computed Tomography
C. Radiotherapy
D. Immunotherapy
View Answer
Answer: Option D
Explanation:
Fluoroscopy, computed tomography, and radiotherapy are techniques that utilize X – rays. Immunotherapy has no relation to X – rays, hence, Immunotherapy is the odd one out.
Question 3
For which of the following path difference, the superimposing waves will not interfere constructively?
A. 3λ
B. 4λ
C. 11λ
D. 11.5λ
View Answer
Answer: Option D
Explanation:
A path difference of 11.5λ between the two waves will not result in constructive interference. For the waves to interfere constructively, the differences in the travel path must be equal to integer multiples of the wavelength.
Question 4
If a beam of X – ray has a wavelength of 1 A°, then what is the energy of this wave?
A. 39.78 x 10-16erg
B. 19.89 x 10-16erg
C. 39.78 x 10-16J
D. 19.89 x 10-16J
View Answer
Question 5
If a beam of X – ray has energy E=30 x 10-16J, what will be the frequency of this wave?
A. 5.523 x 1018 Hz
B. 9.523 x 1018 Hz
C. 8.523 x 1018 Hz
D. 4.523 x 1018 Hz
View Answer
Question 6
In X – ray crystallography, the crystal is gradually rotated and a diffraction pattern is acquired for each distinct orientation.
A. False
B. True
View Answer
Answer: Option B
Explanation:
The above statement is true. In X – ray crystallography, to record a data set the crystal is gradually rotated and a diffraction pattern is acquired for each distinct orientation.
Question 7
The wavelength of X – rays used in X – ray crystallography is 8 x 10-10 m. It undergoes the first-order reflection at a glancing angle of 4.59°. What is the spacing between the atomic planes?
A. 4 x 10-9 m
B. 15 x 10-9 m
C. 10 x 10-9 m
D. 5 x 10-9 m
View Answer
Question 8
What does the interaction of electromagnetic radiation with matter cause the electrons to do?
A. Turn into proton
B. Degrade
C. Move forward
D. Oscillate
View Answer
Answer: Option D
Explanation:
When electromagnetic radiation interacts with matter, it causes the electrons to oscillate. They neither degrade, move forward, or turn into a proton.
Question 9
What does the superposition of waves give rise to?
A. Destructive interference
B. Constructive interference
C. Diffraction
D. Interference
View Answer
Answer: Option D
Explanation:
The accelerated electrons which have interacted with electromagnetic radiation emit radiations of the same frequency as the incident radiation. These radiations are called secondary waves. The superposition of these waves gives rise to interference.
Question 10
What is produced by the analysis of X – ray diffraction data sets?
A. Molecular density maps
B. Nuclei density maps
C. Atom density maps
D. Electron density maps
View Answer
Answer: Option D
Explanation:
Electron density maps are produced by the analysis of X – ray diffraction data sets. This is because the X – rays are diffracted by electrons. These electron density maps are then used to construct the structure of the sample molecule.
Question 11
What is the device on which the crystal (grown in a lab) is mounted known as?
A. X – ray source
B. Collimator
C. Refractometer
D. Goniometer
View Answer
Answer: Option D
Explanation:
A crystal grown in the lab, is mounted on a goniometer and exposed to X – rays produced by rotating anode generators or a synchrotron facility.
Question 12
What is the first step in the X – ray crystallography of proteins?
A. Creating an electron density map
B. X – ray diffraction
C. Precipitation of protein
D. Purification of protein
View Answer
Answer: Option D
Explanation:
Purification of protein is the first step in the X – ray crystallography of proteins. Then the pure protein solution is obtained, which is then used for the precipitation of proteins. Crystals obtained in this step are then irradiated with X – rays and detected by the detector. The last step is to create an electron density map.
Question 13
What is the wavelength range of X – rays?
A. 1 pm to 10 nm
B. 100 pm to 1 nm
C. 1 pm to 1 nm
D. 10 pm to 10 nm
View Answer
Answer: Option D
Explanation:
The wavelength range of X – rays is 10 pm to 10 nm. They have energies in the range of 100 eV to 200 keV. The wavelength of X – rays are shorter than those of UV rays and typically longer than those of gamma rays.
Question 14
Which of the following detector is used for proteins in the X – ray crystallography?
A. Scintillation counters
B. Proportional counters
C. Optical cameras
D. CCD cameras
View Answer
Answer: Option D
Explanation:
CCD cameras are used for proteins in the X – ray crystallography. A diffraction pattern of regularly spaced dots known as reflections is recorded on a detector. CCD cameras/image plates are most frequently used as detectors for protein X – ray crystallography.
Question 15
Which of the following is a form of high energy electromagnetic radiation?
A. UV rays
B. Visible rays
C. Infrared rays
D. X – rays
View Answer
Answer: Option D
Explanation:
X – rays are a form of high energy electromagnetic radiation. UV rays, visible rays, and infrared rays are also electromagnetic radiations but of comparatively lower energy. Different parts of the X-ray spectrum are used in different applications.
Question 16
Which of the following is known as maximum reinforcement in the superposition of waves?
A. Maximum interference
B. Interference
C. Destructive interference
D. Constructive interference
View Answer
Answer: Option D
Explanation:
Constructive interference is known as maximum reinforcement in the superposition of waves. Depending upon the displacement (phase difference) between two waves, the amplitudes either reinforce or cancel out each other.
Question 17
Which of the following is not a component needed for the X – ray crystallography of proteins?
A. Protein crystal
B. Source of X – rays
C. Detector
D. Monochromator
View Answer
Answer: Option D
Explanation:
Monochromator is not a component needed for the X – ray crystallography of proteins. Protein crystal, source of X – rays, and detector are the components needed for the X – ray crystallography of proteins.
Question 18
Which of the following is true for destructive interference?
A. The phase difference of 0°
B. The phase difference of 360°
C. The phase difference of 90°
D. The phase difference of 180°
View Answer
Answer: Option D
Explanation:
When the phase difference between the two interfering waves is 180° it results in destructive interference. Phase differences between 0°, 360°, and 90° do not result in destructive interference.
Question 19
Which of the following radiation is also referred to as Rontgen radiation?
A. Alpha – radiation
B. Beta – radiation
C. Gamma radiation
D. X – radiation
View Answer
Answer: Option D
Explanation:
X – radiation is also referred to as Rontgen radiation. It was named after the German scientist Wilhelm Rontgen. X – radiation has a wavelength range of 10 pm to 10 nm.
Question 20
Which of the following radiations carry enough energy to ionize atoms and disrupt molecular bonds?
A. Visible radiation
B. Infrared radiation
C. UV radiation
D. X – rays
View Answer
Answer: Option D
Explanation:
X – rays carry enough energy to ionize atoms and disrupt molecular bonds. Thus, it belongs to the category of ionizing radiation. These radiations are harmful to living tissue.
Question 21
Which of the following rays can be utilized in cancer treatment to kill malignant cells?
A. Visible rays
B. Infrared rays
C. Gamma rays
D. X – rays
View Answer
Answer: Option D
Explanation:
X – ray scan be utilized in cancer treatment to kill malignant cells. This is known as radiation therapy. Visible rays, infrared rays, and gamma rays cannot be utilized in cancer treatment to kill malignant cells.
Question 22
Which of the following technique is used to investigate the molecular structure through the growth of solid crystals?
A. Radiotherapy
B. Fluoroscopy
C. Computed Tomography
D. X – ray crystallography
View Answer
Answer: Option D
Explanation:
X – ray crystallography is used to investigate the molecular structure through the growth of solid crystals. Radiotherapy, fluoroscopy, and computed tomography have no role in the investigation of molecular structure.
Question 23
Which of the following technique can be used to determine the three-dimensional structure of proteins?
A. Radioimmunoassay
B. Liquid chromatography
C. Mass spectrometry
D. X – ray crystallography
View Answer
Answer: Option D
Explanation:
X-ray crystallography can be used to determine the three-dimensional structure of proteins. Radioimmunoassay, liquid chromatography, and mass spectrometry cannot be used to determine the three-dimensional structure of proteins.
Question 24
Who discovered X – rays?
A. Paul Villard
B. J. J. Thompson
C. Ernest Rutherford
D. Wilhelm Rontgen
View Answer
Answer: Option D
Explanation:
Wilhelm Rontgen discovered X – rays. Hence, it is also known as Rontgen radiation. Paul Villard discovered gamma radiation. Ernest Rutherford discovered beta – radiation. J. J. Thompson first demonstrated cathode rays.
Question 25
X – ray crystallography requires the formation of pure crystals to acquire accurate results.
A. False
B. True
View Answer
Answer: Option B
Explanation:
The above statement is true. X – ray diffraction requires the formation of pure crystals to acquire accurate results. Recrystallization is an incredibly important technique that is used for the purification of a substance.
Question 26
X – rays have a much shorter wavelength than visible light, which makes it possible to probe structures much smaller than that can be seen using a normal microscope.
A. False
B. True
View Answer
Answer: Option B
Explanation:
The above statement is true. X – rays have a much shorter wavelength than visible light, which makes it possible to probe structures much smaller than that can be seen using a normal microscope. This property is used in X-ray crystallography to determine the positions of atoms in crystals.