Engineering Physics Multiple Choice Questions on “Crystal Structure”.
1. X-ray crystallography uses which characteristic of light?
a) Polarization
b) Interference
c) Diffraction
d) Coherency
Answer: c
Clarification: X-ray crystallography is used to identify the molecular and atomic structure of the crystal. The crystal diffracts the incident X-ray beam. By measuring the intensities and angle of these diffracted beams, the molecular structure of the crystal can be evaluated.
2. X-ray crystallography uses which law for its implementation?
a) Einstein’s law
b) Planck’s law
c) Bragg’s law
d) Compton law
Answer: c
Clarification: Bragg’s law is used for the identification of the crystal structure of the lattice. X-ray crystallography used it to identify molecular and/or atomic structure.
3. Which mathematical method is used in X-ray crystallography?
a) Fourier Transform
b) Partial differentiation
c) Geiger method
d) Permutation
Answer: a
Clarification: In X-ray crystallography, the two-dimensional image formed is converted into three-dimensional form using the mathematical concept of Fourier transformation.
4. X-rays scattering in X-ray crystallographic is elastic.
a) True
b) False
Answer: a
Clarification: For all the X-ray diffraction methods used in X-ray crystallography, the scattered X-ray is elastic; the scattered X-ray have the same wavelength as incident X-ray.
5. Which method is used for identifying the crystal structure of Nano-crystalline powders?
a) X-ray crystallography
b) Electron crystallography
c) Gamma-ray crystallography
d) Cannot be identified
Answer: b
Clarification: For Nano-crystalline powders, electron crystallography is used for identifying the atomic structure. X-ray crystallography cannot be used in this case.
6. The synchrotron radiation emitted is Polarized.
a) True
b) False
Answer: a
Clarification: When electrons are accelerated using a synchrotron, radiation called synchrotron radiation is emitted. This radiation is polarized as the electric and magnetic fields of the photons all lie in the same direction.
7. In single X-ray diffraction measurement, the crystal is mounted on __________
a) X-ray source
b) Goniometer
c) Diffraction Plate
d) Fluorescent plate
Answer: b
Clarification: It is only by the diffraction of light when passing through the crystal that the structure of a crystal is identified. The goniometer is a device that is used to position the crystal at selected orientations. In a single-crystal X-ray diffraction measurement, the crystal is mounted on it.
8. Inelastic X-rays scattering method are used for the study of __________
a) Photons
b) Atoms
c) Molecules
d) Phonons
Answer: d
Clarification: Inelastic X-rays scattering method are useful in studying the excitation of samples such a Plasmon, phonon, Magnons, etc. Phonons are quanta of sound waves.
9. XRD stands for _________
a) X-ray diffraction
b) X-rays dispersion
c) X-ray powder diffraction
d) X-ray powder dispersion
Answer: c
Clarification: XRD stands for X-ray powder diffraction. Phase identification of crystalline material can be done using XRD and it can provide information on unit cell dimensions. This technique is utilized in X-ray crystallography.
10. Identify the process.
a) X-ray scan
b) C.T. scan
c) X-ray crystallography
d) X-ray production
Answer: c
Clarification: X-ray crystallography is used to identify the molecular and atomic structure of the crystal. The crystal diffracts the incident X-ray beam. By measuring the intensities and angle of these diffracted beams, the molecular structure of the crystal can be evaluated.