# Nanotechnology Questions and Answers – Nano Optics

This set of Nanotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Nano Optics”.

1. Find out a computational technique which involves direct set of lumped elements in place of a continuous system.
a) Transmission line matrix
b) Monte Carlo method
c) Uniform theory of diffraction
d) Eigenmode expansion

Explanation: Transmission line matrix (TLM) technique has Maxwell’s equations formulated in terms of the scattering of impulses. This model involves space and time discrete electromagnetic phenomenon. Here, the field discretization includes the replacement of a continuous system with a set of lumped elements.

2. Which of the given software’s is based on MOM?
a) HFFS
b) COMSOL
c) MEEP
d) NEC

Explanation: Various softwares are functioning in the market these days with multiple types of methods installed in them to solve real – life complex electromagnetic problems. NEC (Numerical electromagnetic codes) is one among them that uses the method of moments (MOM) and has a PC version named MINIMEC. It’s mostly applied for modeling frequency domain antenna and surface structures.

3. Pick out the odd one out.
a) ▼.D = ρ
b) ▼.g = (ծgx/ծx) + (ծgy/ծy) + (ծgz/ծz)
c) ▼.B = 0
d) ▼x E = – ծB/ծt

Explanation: Computational electromagnetics basically involves solving Maxwell’s equations which include: –
▼.D = ρ…. (i)
▼.B = 0….(ii)
▼x E = – ծB/ծt…. . (iii)
▼x H = J + ծD/ծt …. . (iv)
Here, ▼ = nabla, B and D are magnetic and electric flux densities. E and H are electric and magnetic field intensities, and J is the electric current density.

4. Which of the following is not an advantage of the FIT method?
a) High flexibility in geometry modelling
b) Incorporation of arbitrary material distributions
c) Inclusion of properties such as anisotropy and dispersion
d) Rigidity in boundary handling

Explanation: FIT is advantageous in several ways a) It has high flexibility in geometric modeling and boundary handling; b) It includes arbitrary material distributions; c) It involves properties such as anisotropy, dispersion and non – linearity; d) Generates and computes memory efficient algorithms; e) Adapted for transcient field analysis in radio frequency (RF) applications.

5. Determine the computational method from the given options that involves both simulation and sampling.
a) Method of lines
b) Pseudo – spectral spatial domain
c) Transmission line matrix
d) Monte Carlo method

Explanation: Monte Carlo method, a non – deterministic numerical approach incorporates two ways – sampling and simulations. Sampling indulges in methods of determining properties of a large set of elements by analyzing only a small subset. Simulation, on the other hand, deals with procedures of providing mathematical emulation of some real – life instances.

6. Who introduced the Fast multipole method?
a) Krätschmer and Huffman
b) Greengard and Rokhlin
c) Iijima and Smalley
d) Geim and Novoselov

Explanation: The Fast multipole method was introduced for the first time by Greengard and Rokhlin. It’s an alternative to MoM or Ewald summation. This technique can even accelerate MoM. It is based on multipole expansion technique.

7. Identify an antenna simulation software from the following that is based on method of moments.
a) COMSOL
b) Max Fem
c) FEKO
d) HFFS

Explanation: FEKO is computational electromagnetics software based on method of moments. It is an antenna simulation software that can also be used as a general purpose 3D electromagnetic simulator. Other uses involve the calculation of radiation pattern and impedance.

8. Which method of computational electromagnetics is used to compute scattering and absorption by targets?
a) MoM
b) BEM
c) DDA
d) FIT

Explanation: The discrete dipole approximation (DDA) method, frequently referred to as coupled dipole approximation, is used for computing scattering and absorption by targets of arbitrary geometry. It is based on the integral form of Maxwell’s equation. This method approximates the continuum target by a bounded array of polarization points.

9. Physical optics is a computational method applying wave effects for high frequency or short wavelength approximation.
a) True
b) False

Explanation: Physical optics is a high frequency or short wavelength approximation used in optics, electrical engineering and applied physics. This method is considered to be an intermediate of full wave electromagnetism and geometric optics. It ignores wave effects. It uses ray optics to calculate the transmitted or scattered field.

10. What is the computational method on which the software COMSOL is based?
a) FEM
b) UTD
c) EME
d) BEM

Explanation: COMSOL is a finite element method based software. It offers a conventional physics based user interface and coupled systems of partial differential equations (PDEs) . It also provides an integrated development environment for electrical, chemical, and mechanical applications.

11. What is the full form of MRTD, a computational method based on wavelet analysis?
a) Minimum solvable temperature difference
b) Magnetic resonance technology discovery
c) Multiresolution time domain
d) Morbidity rate with temporary disability

Explanation: MRTD stands for Multiresolution time domain. This technique is an alternative to FDTD method. It makes use of wavelet analysis to represent EM fields. The wavelets permit the alteration of resolution of the simulation as a function of both time and space.

12. Identify the odd one out.
a) EMAP
b) Sonnet
c) MoM
d) MaxFem

Explanation: There are different commercial softwares developed inorder to design and solve complicated electromagnetic problems both in industries and academics. These softwares include EMAP, COMSOL, MaxFem, Sonnet etc. However, MoM, method of moments, is a technique that is installed in some of these software’s for solving the real – life problems.

More MCQs on Nano-Optics:

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