McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Electrical Engineering , Chemical Engineering .
| 1. |
Nanomaterials are the materials with at least one dimension measuring less than |
| A. | 1 nm |
| B. | 10 nm |
| C. | 100 nm |
| D. | 1000 nm |
| Answer» C. 100 nm | |
| Explanation: a material with at least one of its dimensions measuring less than 100 nm (1 to 100nm) are classified as nanomaterials. | |
| 2. |
A material with one dimension in Nano range and the other two dimensions are large is called |
| A. | micro-material |
| B. | quantum wire |
| C. | quantum well |
| D. | quantum dot |
| Answer» C. quantum well | |
| Explanation: such a material with one dimension in nano range and other two large is called quantum well. a material with two of the three dimensions in the nano range and third large is called quantum wire. when all the dimensions are in nano range, it is called quantum dot. | |
| 3. |
The colour of the nano gold particles is |
| A. | yellow |
| B. | orange |
| C. | red |
| D. | variable |
| Answer» D. variable | |
| Explanation: the colour of the nano gold particle varies with the size of the particles. it shows different colours like orange, red, purple, or greenish. | |
| 4. |
The melting point of particles in nano form |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | increases then decreases |
| Answer» B. decreases | |
| Explanation: for the particles in the nano form, the melting point reduces significantly. other chemical properties are also changed as the dimensions of the object comes in the nano range. | |
| 5. |
The first talk about nano-technology was given by |
| A. | albert einstein |
| B. | newton |
| C. | gordon e. moore |
| D. | richard feynman |
| Answer» D. richard feynman | |
| Explanation: in 1959, richer feynman gave a speech in which he spoke of nano-science and nano-technology. he talked about the possibility of manipulating individual atoms and molecules. | |
| 6. |
Which of the processes of materials was not described as Nanotechnology? |
| A. | separation |
| B. | creation |
| C. | processing |
| D. | consolidation |
| Answer» B. creation | |
| Explanation: nanotechnology, as defined by professor n. taniguchi, consists of the processing, separation, consolidation and deformation of materials by one atom or by one molecule. it is used exclusively for the nanomaterials. | |
| 7. |
The initial tools used to help launch the nanoscience revolution were |
| A. | binoculars |
| B. | microscope |
| C. | scanning probe instruments |
| D. | interferometer |
| Answer» C. scanning probe instruments | |
| Explanation: scanning probe instruments were the initial tools used by the scientist. in these instruments, the probe slides along the surface of the specimen. | |
| 8. |
When semiconductors are reduced to nanometres they become pure conductors. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: when semiconductors are reduced to the nano form their chemical properties change significantly and they become insulators, as there is no more space for free electrons to move. | |
| 9. |
The major difference between the nano materials compared to the bulk form is the big fraction of the total number of atoms on the surface. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: as the bulk material is changed into nano form, the number of atoms on the surface turns out to be a large fraction of the total number of atoms present in the material. | |
| 10. |
The size of atoms is nearly |
| A. | 0.01 nm |
| B. | 0.1 nm |
| C. | 1 nm |
| D. | 10 nm |
| Answer» B. 0.1 nm | |
| Explanation: the size of the atoms is nearly | |
| 11. |
The four types of Artificial nanomaterials are |
| A. | carbon-based, non-metallic, composites and ceramics |
| B. | carbon-based, metallic, composites and ceramics |
| C. | carbon-based, non-metallic, composites and dendrimers |
| D. | carbon-based, metallic, composites and dendrimers |
| Answer» D. carbon-based, metallic, composites and dendrimers | |
| Explanation: artificial nanomaterials can be divided into four categories – carbon-based, metal-based, dendrimers and composites. the other types of nanomaterials are called natural nanomaterials. | |
| 12. |
Solution of pure buckminsterfullerene has a colour of |
| A. | green |
| B. | purple |
| C. | pink |
| D. | yellow |
| Answer» B. purple | |
| Explanation: solutions of pure c60 have a deep purple colour. they are a class of allotropes of carbon which conceptually are graphene sheets rolled into spheres. | |
| 13. |
HyFn stands for |
| A. | hydrated fluorine |
| B. | hydrolysed fluorine |
| C. | hydrolysed fullerene |
| D. | hydrated fullerene |
| Answer» D. hydrated fullerene | |
| Explanation: hyfn stands for hydrated fullerene. it is a stable, highly hydrophilic, super-molecular complex consisting of c60 molecules. | |
| 14. |
Nano sized polymers built from branched units are called |
| A. | dendrimers |
| B. | composites |
| C. | carbon-based materials |
| D. | metal-based materials |
| Answer» A. dendrimers | |
| Explanation: the nano-sized polymers built from branched units are called dendrimers. the dendrimers can be used to perform many chemical functions, such as catalysis, as it has numerous chain ends. | |
| 15. |
Which property of nanoparticles provides a driving force for diffusion? |
| A. | optical properties |
| B. | high surface area to volume ratio |
| C. | sintering |
| D. | there is no such property |
| Answer» B. high surface area to volume ratio | |
| Explanation: the nanoparticles provide a high driving force for diffusion, as it has a high surface area to volume ratio. this driving force is even higher at elevated temperatures. | |
| 16. |
On both ends of the CNTs, which carbon nanostructure is placed? |
| A. | graphite |
| B. | diamond |
| C. | c60 |
| D. | benzene |
| Answer» C. c60 | |
| Explanation: carbon nanotubes, cnts, are nanostructures with large application potential. its structure consists of a single sheet of graphite rolled into a tube. the ends of the cnts are capped with c60 hemispheres. | |
| 17. |
Quantum dots can be used in |
| A. | crystallography |
| B. | optoelectronics |
| C. | mechanics |
| D. | quantum physics |
| Answer» B. optoelectronics | |
| Explanation: quantum dots are basically semiconductor nanoparticles that show a particular colour on illumination by a light. they have unique electrical and optical properties. due to this, they are widely used in optoelectronics. | |
| 18. |
Vesicle is a type of |
| A. | nanostructure |
| B. | nanoparticle |
| C. | nanocrystal |
| D. | supramolecular system |
| Answer» D. supramolecular system | |
| Explanation: vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of man different molecules. they can be formed naturally as well as artificially. | |
| 19. |
The response of a material due to the function of heat is known as |
| A. | mechanical property |
| B. | electrical property |
| C. | chemical property |
| D. | thermal property |
| Answer» D. thermal property | |
| Explanation: mechanical properties deal with the effects of external forces, while electric properties deal with the effect of the flow of electricity, and chemical properties are related to a material’s effects due to reaction with other substances. thermal properties deal with heat and temperature effects on the material. | |
| 20. |
Specific heat of materials is expressed in terms of |
| A. | w/m k |
| B. | j/k |
| C. | j/kg k |
| D. | m3/kg |
| Answer» C. j/kg k | |
| Explanation: specific heat capacity of a material is an intensive property expressed in terms of j/kg k. thermal conductivity, heat capacity, and specific volume are expressed in terms of w/m k, j/k, and m3/kg correspondingly. | |
| 21. |
What effect does the addition of thermal energy have on a material? |
| A. | thermal contraction |
| B. | thermal expansion |
| C. | no change |
| D. | reproduction |
| Answer» B. thermal expansion | |
| Explanation: addition of heat or thermal energy results in an increase in magnitude as a theory of basic laws of thermodynamics. hence, on the addition of thermal energy, thermal expansion occurs. | |
| 22. |
Which term is used to define the temperature at which a substance changes its status from solid to liquid? |
| A. | boiling point |
| B. | melting point |
| C. | condensation point |
| D. | freezing point |
| Answer» B. melting point | |
| Explanation: the temperature at which a substance changes from solid state to liquid is known as the melting point; here the temperatures of solid and liquid are in equilibrium. the shift of liquid state to solid is known as the freezing point. the transition from gaseous state to liquid is known as | |
| 23. |
The melting point of Iron (Fe) is |
| A. | 660oc |
| B. | 1084oc |
| C. | 419oc |
| D. | 1538oc |
| Answer» D. 1538oc | |
| Explanation: the melting point of iron is 1538oc, whereas the melting points of aluminum (al), zinc (zn), and copper (cu) are 660oc, 419oc, and 1084oc in that order. | |
| 24. |
What effect do thermal variations in volume have on a body? |
| A. | expansion |
| B. | contraction |
| C. | cracking |
| D. | phase transformation |
| Answer» C. cracking | |
| Explanation: cracking is the effect of thermal variation in the volume of a body. expansion, contraction, and phase transformation are the ways in which these volume changes occur, i.e. they are causes, and not effects. | |
| 25. |
The temperature at which plastics begin to become softer and defer under a load is known as |
| A. | softening point |
| B. | melting point |
| C. | eutectic point |
| D. | heat distortion point |
| Answer» D. heat distortion point | |
| Explanation: heat distortion point is the temperature at which plastics begin to become softer and defer under a load. the softening point is the temperature at which a flat-ended needle of 1 mm2 penetrates the test same at 1 mm2 depth. eutectic point the temperature at which a mixture freezes or melts. the melting point is the temperature at which the state of the body changes from solid to liquid. | |
| 26. |
What’s the procedure in Top-down fabrication method? |
| A. | nano-particles -> powder -> bulk |
| B. | powder -> bulk – > nano-particles |
| C. | bulk -> powder – > nano-particles |
| D. | nano-particle – > bulk -> powder |
| Answer» C. bulk -> powder – > nano-particles | |
| Explanation: top-down approach is the one in which a material of regular size is converted into a nano-particle. in the bottom-up approach, the atoms are joined to form nano-particles. | |
| 27. |
Which of the following is an example of Bottom Up approach? |
| A. | attrition |
| B. | colloidal dispersion |
| C. | milling |
| D. | etching |
| Answer» B. colloidal dispersion | |
| Explanation: colloidal dispersion is an example of bottom up approach in the synthesis of nano particles. attrition, milling and etching are typical top down methods. | |
| 28. |
For milling operations, what kind of environment is preferred? |
| A. | acidic |
| B. | basic |
| C. | active |
| D. | inert |
| Answer» D. inert | |
| Explanation: milling is the process of particle size reduction with the objective of mixing or blending and change of particle size. an inert environment is preferred for this process. | |
| 29. |
What kind of metals are used for milling operations? |
| A. | soft and brittle |
| B. | soft and elastic |
| C. | hard and brittle |
| D. | hard and elastic |
| Answer» C. hard and brittle | |
| Explanation: for the milling operation, normally hard brittle materials with fracture, deform and cold weld are used. the reason for choosing dense materials is the fact that the kinetic energy of balls depends upon their mass and velocity. | |
| 30. |
The following flow chart is for which method? |
| A. | milling |
| B. | attrition |
| C. | pattering |
| D. | microfabrication |
| Answer» D. microfabrication | |
| Explanation: the given process is the process of microfabrication. the water is prepared and then photoresist is applied. the product is exposed to the uv light which after a series of processes, results in the fabrication of nanomaterials. | |
| 31. |
CVD stands for |
| A. | carbon vapour density |
| B. | chemical vapour density |
| C. | chemical vapour deposition |
| D. | carbon vapour deposition |
| Answer» C. chemical vapour deposition | |
| Explanation: chemical vapour deposition, or cvd, is a chemical process used to produce high-purity, high-performance solid materials. the process is often used to produce carbon nanotubes. | |
| 32. |
Photolithography is a type of patterning technique. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: photolithography has been the predominant patterning technique for a long time. it will require the use liquid immersion and a host of resolution enhancement technologies. | |
| 33. |
Chemical solution deposition is also known as |
| A. | sol-gel |
| B. | cvd |
| C. | plasma spraying |
| D. | laser pyrolysis |
| Answer» A. sol-gel | |
| Explanation: sol-gel, or chemical solution deposition, is used primarily for the fabrication of material starting from a chemical solution that acts as the precursor for an integrated network. | |
| 34. |
Typical precursor used in sol-gel are |
| A. | metal oxides |
| B. | metal dioxides |
| C. | metal alkoxides |
| D. | metal fluorides |
| Answer» C. metal alkoxides | |
| Explanation: metal alkoxides and metal chlorides are basically used as precursors in sol- gel. furthermore, a colloidal suspension is formed when they undergo hydrolysis or poly- condensation. | |
| 35. |
The following is a bottom-up process. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: sol-gel is a bottom-up approach in which a precursor is used to for wither a network or a colloidal suspension, so as to form desired nanoparticles. | |
| 36. |
Particles of ZrO2, Y2O2 and Nano whiskers have been produced by |
| A. | sol-gel |
| B. | cvc |
| C. | plasma spraying |
| D. | laser pyrolysis |
| Answer» B. cvc | |
| Explanation: cvc stands for chemical vapour condensation. it involves pyrolysis of vapours of metal organic precursors in a reduced pressure atmosphere. | |
| 37. |
Which gas serves as buffer gas in Laser ablation? |
| A. | nitrogen |
| B. | oxygen |
| C. | helium |
| D. | neon |
| Answer» C. helium | |
| Explanation: laser ablation has been extensively used for the preparation of nanoparticles. in the device, there is a pulsed flow of helium gas. it serves as a buffer gas in which clusters of the target material form, thermalize. | |
| 38. |
Which of the following is an unconventional process of machining? |
| A. | milling |
| B. | usm |
| C. | drilling |
| D. | none of the mentioned |
| Answer» B. usm | |
| Explanation: usm stands for ultrasonic machining process and it is an unconventional process of machining. | |
| 39. |
Ultrasonic machining process can be used for |
| A. | conductors |
| B. | insulators |
| C. | metals |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: ultrasonic machining is more versatile and can be used for the metal as well as non metal. | |
| 40. |
Which of the following is a conventional process of machining? |
| A. | electro chemical machining |
| B. | electron beam machining |
| C. | ultrasonic machining |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| Explanation: all of the mentioned are unconventional process of machining. | |
| 41. |
For machining of plastic material which of the unconventional process can be used effectively? |
| A. | electro chemical machining |
| B. | electron beam machining |
| C. | ultrasonic machining |
| D. | none of the mentioned |
| Answer» C. ultrasonic machining | |
| Explanation: ultrasonic machining is more versatile and can be used for the metal as well as non metal. | |
| 42. |
Material removal rate in USM increases with |
| A. | decrease in volume of work material per impact |
| B. | increase in volume of work material per impact |
| C. | decrease in frequency |
| D. | decrease in number of particle making impact per cycle |
| Answer» B. increase in volume of work material per impact | |
| Explanation: material removal rate in usm is proportional to the volume of work material per impact. | |
| 43. |
Material removal rate in USM increases with |
| A. | decrease in volume of work material per impact |
| B. | decrease in volume of work material per impact |
| C. | decrease in frequency |
| D. | increase in number of particle making impact per cycle |
| Answer» D. increase in number of particle making impact per cycle | |
| Explanation: material removal rate in usm is proportional to the number of particle making impact per cycle. | |
| 44. |
Material removal rate in USM increases with |
| A. | decrease in volume of work material per impact |
| B. | decrease in volume of work material per impact |
| C. | increases in frequency |
| D. | decreases in the number of particle making impact per cycle |
| Answer» C. increases in frequency | |
| Explanation: material removal rate in ultrasonic machining is proportional to frequency. | |
| 45. |
Element of machine which is used to convert high frequency electrical impulse into mechanical vibration in USM is known as |
| A. | tool |
| B. | feeding unit |
| C. | transducer |
| D. | none of the mentioned |
| Answer» C. transducer | |
| Explanation: transducer is a device which is used to convert one form of energy to other. | |
| 46. |
Which of the following elements of USM is used to apply working force during machining operation? |
| A. | tool |
| B. | feeding unit |
| C. | transducer |
| D. | none of the mentioned |
| Answer» B. feeding unit | |
| Explanation: feeding unit is used to apply working force during a machining operation. | |
| 47. |
Material removal rate in USM increases with |
| A. | decrease in amplitude |
| B. | decrease in grain size of abrasives |
| C. | decrease in frequency |
| D. | increase in amplitude |
| Answer» D. increase in amplitude | |
| Explanation: material removal rate in ultrasonic machining is proportional to amplitude. | |
| 48. |
3 COLLOIDAL ROUTES, SELF-ASSEMBLY |
| A. | 10-20 nm |
| B. | more than 20 nm |
| C. | less than 10 nm |
| D. | 30 to 50 nm |
| Answer» A. 10-20 nm | |
| Explanation: since colloidal are intermediate between powdered particles and suspension particles, they have a size in between these particles of about 10 to 20 nm. these are considered to be intermediate size of molecules. | |
| 49. |
Which of the following is a characteristic of a colloid? |
| A. | it forms 2 layers with a solution |
| B. | it forms turbid layers |
| C. | it forms heterogeneous layer |
| D. | it forms a homogeneous layer |
| Answer» B. it forms turbid layers | |
| Explanation: since a colloidal particle does not from a single layer with solvents, the only possibility is to form a turbid layer where the solution is an intermediate between a miscible and immiscible solution. | |
| 50. |
Where does colloidal solution find application in? |
| A. | in milk industries |
| B. | in chromatic chemical industries |
| C. | in crystallography |
| D. | in textiles |
| Answer» A. in milk industries | |
| Explanation: since colloidal solutions can easily be emulsified with the help of emulsifying agents such as ethylene dichloride, it can find its major application in the field of dairy industries. | |
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