Fundamentals Of Nanoscience Set 4

Electrical Engineering,

Chemical Engineering

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This set of Fundamentals of NanoScience Multiple Choice Questions & Answers (MCQs) focuses on Fundamentals Of Nanoscience Set 4

Q1 | An ancient process used till today for production of circuit films is,
  • silk screening technique
  • surface mount technology
  • ceramic printing technique
  • screen printing technique
Answer: screen printing technique
Explaination:
the process of screen printing pattern is an ancient one. the egyptian used this technique thousands of years ago to decrease potter and wall of building.
Q2 | What is the advantage of using Surface Mount Technology?
  • all of the mentioned
  • low power consumption
  • reduces heat dissipation in components
  • use leaded or leadless components
Answer: use leaded or leadless components
Explaination:
surface mount technology utilizes micro-miniature leaded or leadless components called surface mount device (smd) which are directly soldered to the specified areas on the surface without hole. also, the compact size of smds reduces the area in pcb and increases the packing density.
Q3 | Which of the following is an example of top- down approach for the preparation of nanomaterials?
  • gas phase agglomeration
  • molecular self-assembly
  • mechanical grinding
  • molecular beam epitaxy
Answer: mechanical grinding
Explaination:
mechanical grinding is an example of top-down approach for the preparation of nanomaterials. all the other options are the example of bottom-up approach.
Q4 | Which of the following is an example of bottom-up approach for the preparation of nanomaterials?
  • etching
  • dip pen nano-lithography
  • lithography
  • erosion
Answer: dip pen nano-lithography
Explaination:
dip pen nanolithography is an example of bottom-down approach for the preparation of nanomaterials. all the other options are the example of top-down approach.
Q5 | The properties like melting point, solubility, color, etc changes on varying the                        
  • size
  • composition
  • surface properties
  • none of the mentioned
Answer: size
Explaination:
the properties like melting point, solubility, color, etc changes on varying the size of the particles. these all are the physical properties and depends upon the physical characteristics of the particle.
Q6 | The properties like dispersibility, conductivity, etc changes on varying the
  • size
  • composition
  • surface properties
  • none of the mentioned
Answer: surface properties
Explaination:
the properties like dispersibility, conductivity, etc changes on varying the surface properties of the nanoparticle. these all are the chemical properties and depend upon the surface characteristics of the particle.
Q7 | Quantum confinement results in
  • energy gap in semiconductor is proportional to the inverse of the square root of the size
  • energy gap in semiconductor is proportional to the inverse of the size
  • energy gap in semiconductor is proportional to the square of size
  • energy gap in semiconductor is proportional to the inverse of the square of size
Answer: energy gap in semiconductor is proportional to the inverse of the square of size
Explaination:
the energy gap in a semiconductor is proportional to the inverse of the square of the size. this effect is a result of quantum confinement.
Q8 | Which of the following is the principal factor which causes the properties of nanomaterials to differ significantly from other materials?
  • size distribution
  • specific surface feature
  • quantum size effects
  • all of the mentioned
Answer: all of the mentioned
Explaination:
size distribution, specific surface feature and quantum size effects are the principal factor which causes the properties of nanomaterials to differ significantly from other materials.
Q9 | Select the incorrect statement from the following options.
  • self-assembly is a top-down manufacturing technique
  • in self-assembly, weak interactions play very important role
  • self-assembling molecules adopt an organised structure which is thermodynamically more stable than the single, unassembled components
  • compared to the isolated components, the self-assembled structure has a higher order
Answer: self-assembly is a top-down manufacturing technique
Explaination:
self-assembly is a bottom-down manufacturing technique. all the other options are correct. in self-assembly, weak interactions play very important role, self-assembling
Q10 | Which of the following is the application of nanotechnology to food science and technology?
  • agriculture
  • food safety and biosecurity
  • product development
  • all of the mentioned
Answer: all of the mentioned
Explaination:
the application of nanotechnology to food science and technology are agriculture, food safety and biosecurity, product development, food processing and ingredient technologies.
Q11 | What are the advantages of nano-composite packages?
  • lighter and biodegradable
  • enhanced thermal stability, conductivity and mechanical strength
  • gas barrier properties
  • all of the mentioned
Answer: all of the mentioned
Explaination:
the advantages of nano- composite packages are-lighter and biodegradable, enhanced thermal stability, conductivity, mechanical strength and gas barrier properties.
Q12 | The efficiency of today’s best solar cell is about                        
  • 15-20%
  • 40%
  • 50%
  • 75%
Answer: 40%
Explaination:
the efficiency of today’s best solar cells is about 40%. a solar cell or photovoltaic cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.
Q13 | The configuration of Buckminsterfullerene is
  • 12 hexagons and 22 pentagons
  • 18 hexagons and 15 pentagon
  • 20 hexagon and 12 pentagon
  • 15 hexagon and 15 pentagon
Answer: 20 hexagon and 12 pentagon
Explaination:
buckminsterfullerene, commonly known as fullerene, consists of 20 hexagons and 12 pentagons, which are arrayed such that no two pentagons share a common side.
Q14 | C60 is soluble in                          
  • water
  • ammonia
  • hcl
  • benzene
Answer: benzene
Explaination:
c60 molecules are held together by weak van der waal’s forces. they are insoluble in ionic solvents like water, ammonia and hcl, as it is non-ionic. as it is an organic molecule, it is soluble in benzene.
Q15 | CNTs stands for                          
  • carbon nanotubes
  • carbon nanotechnology
  • carbon nanoscience and technology
  • carbon nine technology
Answer: carbon nanotubes
Explaination:
carbon nanotubes, cnts, are nanostructures with large application potential. its structure consists of a single sheet of graphite rolled into a tube.
Q16 | CNTs are capped on both ends with which carbon nanostructure?
  • graphite
  • diamond
  • c60
  • benzene
Answer: c60
Explaination:
carbon nanotubes are basically a single sheet of graphite, which is rolled into a tube. the ends of the cnts are covered by the c60 hemispheres. such is the construction of a cnt.
Q17 | The metallic tubes have which kind of structure?
  • armchair
  • chiral
  • boat
  • achiral
Answer: armchair
Explaination:
the cnts are often a mixture of semiconducting and metallic tubes. while the metallic tubes have armchair structure, the semiconducting tubes have a chiral structure.
Q18 | The carbon tubes have high conductivity.
  • true
  • false
Answer: true
Explaination:
the reason for the high conductivity of the carbon nanotubes is that they have very few defects to scatter electrons and therefore show very low resistance.
Q19 | Carbon nanotubes display magnetoresistance at low temperature.
  • true
  • false
Answer: true
Explaination:
magnetoresistance is the phenomenon in which the resistance of a material changes on the application of a magnetic field. carbon nanotubes display this property at low temperature. in fact, it shows negative magnetoresistance as the resistance decreases with an increasing magnetic field.
Q20 | Identify the process.
  • synthesis of c60
  • synthesis of cnts
  • chemical vapour deposition
  • carbon discharge
Answer: synthesis of cnts
Explaination:
the given figure shows the schematic diagram for synthesis of cnt by laser evaporation. the quartz tube is heated to 1200°. a water called copper collection is present at the end to cool it down.
Q21 | The main purpose of CNTs in fuel cells is
  • production of energy
  • active medium
  • catalyst
  • storage
Answer: storage
Explaination:
carbon nanotubes are useful in
Q22 | The figure shows a FET using CNT. Identify CNT.
  • bucky balls
  • soccer balls
  • cricket balls
  • tennis balls
Answer: bucky balls
Explaination:
spherical fullerenes are otherwise called as the bucky balls. they resemble to the
Q23 | The fullerenes are composed with                    
  • graphene sheets
  • graphite
  • lead
  • other carbon materials
Answer: graphene sheets
Explaination:
the fullerenes are composed with stalked graphene sheets. the fullerenes are similar to the structure of graphite. the only difference is they can be n sphere, tube or ellipsoid but graphene is layers.
Q24 | In fullerenes, the graphene sheets are linked with                  
  • hexagonal rings
  • octagonal rings
  • trigonal rings
  • decagonal rings
Answer: hexagonal rings
Explaination:
the fullerenes are composed with the stalked graphite sheets that are linked with the hexagonal ring. they may also be linked with the pentagonal and heptagonal rings sometimes.
Q25 | The smallest bucky ball cluster is                    
  • c6
  • c8
  • c10
  • c20
Answer: c20
Explaination:
the smallest bucky ball cluster is
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