McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Electrical Engineering , Chemical Engineering .
| 51. |
During an experiment, accidently iodine got mixed up with a biological sample of proteins and polys. Identify the smallest colloid that can be obtained during the process of separation. |
| A. | fats |
| B. | amino acids |
| C. | polys |
| D. | r molecules |
| Answer» B. amino acids | |
| Explanation: given that the solution of iodine got mixed up with milk sample, we know milk is already a colloidal solution of polymers like amino acids, proteins, fats, vitamins etc, the smallest among all these colloidal particles is amino acids. | |
| 52. |
Which of the following form of colloid is considered to be the strongest colloid? |
| A. | gel |
| B. | foam |
| C. | solid sol |
| D. | liquid sol |
| Answer» C. solid sol | |
| Explanation: we know that solid sol is the colloidal solution of a solid and a solid. since there is a mixture of solid and solid, the bond between them is quite strong. thus it is considered to be the strongest colloid. | |
| 53. |
Which of the following form of colloid is considered to be the lightest colloid? |
| A. | gaseous foam |
| B. | solid sol |
| C. | sol |
| D. | liquid sol |
| Answer» A. gaseous foam | |
| Explanation: we know that the gaseous foam is the colloidal solution of gaseous molecules and liquid. thus there exists a lighter bond between the particles. thus this is considered as the lightest colloid. | |
| 54. |
What is the size of normal an amino acid? |
| A. | 1 to 2 nm |
| B. | 2 to 3 nm |
| C. | 4 to 5 nm |
| D. | 2 to 5 nm |
| Answer» A. 1 to 2 nm | |
| Explanation: we know that amino acids are nothing but single structure monomers of proteins. thus they are visible only under an ultra microscope due to is an extreme small size in the range of nano meters. their size ranges from 1 to 2 nm. | |
| 55. |
What is called a dispersion phase? |
| A. | it is the main layer |
| B. | it is the secondary layer in which the colloidal particles are dispersed |
| C. | it is the secondary layer |
| D. | it is the basic colloidal layer |
| Answer» B. it is the secondary layer in which the colloidal particles are dispersed | |
| Explanation: since the colloidal particles require a layer in which it has to be dispersed, the dispersion phase is considered to be a second layer. the dispersion phase is generally a solvent. | |
| 56. |
What is called a dispersion medium? |
| A. | it is where the dispersed phase settles |
| B. | it is where the solute particles settle |
| C. | it is where the dispersed phase is suspended |
| D. | it is the primary medium |
| Answer» C. it is where the dispersed phase is suspended | |
| Explanation: since to form a stable colloidal solution, the dispersed phase requires a stable solvent medium is required. this is the condition in which equilibrium is achieved. | |
| 57. |
Which of the following is not a technique for fabrication of glass fibers? |
| A. | vapor phase oxidation method |
| B. | direct melt method |
| C. | lave ring method |
| D. | chemical vapor deposition technique |
| Answer» C. lave ring method | |
| Explanation: lave ring method refers to the deposition of a crystalline layer on a substrate. all the other methods, except lave ring method, refer to optical fiber fabrication. | |
| 58. |
technique is method of preparing extremely pure optical glasses. |
| A. | liquid phase (melting) |
| B. | radio frequency induction |
| C. | optical attenuation |
| D. | vapor phase deposition (vpd) |
| Answer» D. vapor phase deposition (vpd) | |
| Explanation: vapor phase deposition techniques are used to prepare silica-rich glasses. these glasses exhibit highest transparency and optimal optical properties. | |
| 59. |
Which of the following materials is not used as a starting material in vapor-phase deposition technique? |
| A. | sicl4 |
| B. | gecl4 |
| C. | o2 |
| D. | b2o3 |
| Answer» D. b2o3 | |
| Explanation: in vapor-phase deposition technique, starting materials are volatile organic compounds. these materials are distilled to reduce the concentration of transition metal impurities. b2o3 is used as a dopant. | |
| 60. |
P2O5 is used as a |
| A. | dopant |
| B. | starting material |
| C. | cladding glass |
| D. | core glass |
| Answer» A. dopant | |
| Explanation: p2o5 is a non silica material. dopants are formed from non silica materials so that refractive index modification is achieved. | |
| 61. |
How many types of vapor-phase deposition techniques are present? |
| A. | one |
| B. | two |
| C. | three |
| D. | four |
| Answer» B. two | |
| Explanation: vapor-phase deposition techniques are divided into two types. the two types are flame hydrolysis and chemical vapor deposition (cvd). further, these two types are subdivided into two more sections. | |
| 62. |
uses flame hydrolysis stems from work on soot processes which were used to prepare the fiber with losses below 20 dB/km. |
| A. | outside vapor phase oxidation |
| B. | chemical vapor deposition |
| C. | liquid phase melting |
| D. | crystallization |
| Answer» A. outside vapor phase oxidation | |
| Explanation: outside vapor phase oxidation is a type of vapor flame hydrolysis. it was originally developed by hyde. in this process, the glass composition is deposited from a ‘soot’ generated by hydrolyzing the halide vapors in an oxygen-hydrogen flame. | |
| 63. |
In modified chemical vapor deposition, vapor phase reactant such as pass through a hot zone. |
| A. | halide and oxygen |
| B. | halide and hydrogen |
| C. | halide and silica |
| D. | hydroxides and oxygen |
| Answer» A. halide and oxygen | |
| Explanation: halide and oxygen are passed through the hot zone during chemical vapor deposition. glass particles formed during this travel are deposited on the walls of silica tube which are moved back and forth allowing the particles to deposit layer by layer. | |
| 64. |
is the stimulation of oxide formation by means of non-isothermal plasma maintained at low pressure in a microwave cavity surrounding the tube. |
| A. | outside vapor phase oxidation (ovpo) |
| B. | vapor axial deposition (vad) |
| C. | modified chemical vapor deposition (mcvd) |
| D. | plasma-activated chemical vapor deposition (pcvd) |
| Answer» D. plasma-activated chemical vapor deposition (pcvd) | |
| Explanation: pcvd method was first developed by cuppers and koenig’s. it involves a plasma-induced chemical vapor deposition inside a silica tube. it is different from mcvd process as it involves stimulation of oxide formation by means of non-isothermal plasma. | |
| 65. |
Only graded index fibers are made with the help of vapor-phase deposition techniques. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: vapor phase deposition techniques are used for preparation of both step- index and graded index fibers. these techniques provide fibers with low attenuation losses. also, it gives similar performance for the fabrication of both single mode and multimode fibers. | |
| 66. |
Modified Chemical Vapor Deposition (MCVD) process is also called as an inside vapor phase oxidation (IVPD) technique. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: mcvd process was developed by bell telephone laboratories and southampton university, uk. it is called as inside vapor phase oxidation (ivpo) as it takes place inside the silica tube at the temperatures between 1400 and 1600 degrees celsius. | |
| 67. |
When does an integrated circuit exhibit greater degree of freedom and electrical performance? |
| A. | in thin and thick film technology |
| B. | in semiconductor technology |
| C. | in semiconductor and films technology |
| D. | in thick film technology only |
| Answer» C. in semiconductor and films technology | |
| Explanation: combining films and semiconductor technology provide a better electrical performance than either technology can provide separately. | |
| 68. |
Give the thickness range of the film used in thin film technology |
| A. | 0.5-2.5 mils |
| B. | 0.02-8 mils |
| C. | 10-20 mils |
| D. | 0.05-0.0 7mils |
| Answer» B. 0.02-8 mils | |
| Explanation: thin films have thickness varying from 50 Å to 20,000 Å. | |
| 69. |
Which technology is used to get cheap resistors and capacitors? |
| A. | thick film technology |
| B. | thin film technology |
| C. | thin and thick film technology |
| D. | none of the mentioned |
| Answer» B. thin film technology | |
| Explanation: thick film technology produces cheap and rugged components, whereas thin film technology provides greater precision in manufacturing but is quite expensive. the processing equipment for thick film circuit is relatively inexpensive and is easy to use. | |
| 70. |
How is the process of film deposition carried out in cathode sputtering? |
| A. | slower than evaporation method |
| B. | faster than evaporation method |
| C. | similar to same as evaporation method |
| D. | all of the mentioned |
| Answer» A. slower than evaporation method | |
| Explanation: cathode sputtering and vacuum evaporation uses identical system. however, the process of film deposition in cathode sputtering is slower than evaporation method. since depositing a micron-thick film takes minutes to hours, compared to seconds to minutes for evaporation. | |
| 71. |
How a uniform film with good crystal structure is attained in cathode sputtering process? |
| A. | by hitting high energy particle directly on the substrate |
| B. | allowing less time for the particles to deposit on the substrate |
| C. | high energy particle diffuse through low pressure gas and deposits on the substrate |
| D. | heavy inert gas is used for film deposition on the substrate |
| Answer» C. high energy particle diffuse through low pressure gas and deposits on the substrate | |
| Explanation: the process of cathode sputtering is performed at a low pressure (about 10-12 torr). so, when the high energy particle landing on the substrate actually results in a very uniform film and adhesion. | |
| 72. |
Which process is used to deposit metals on glass, ceramic and plastic? |
| A. | silk plating technique |
| B. | gas plating technique |
| C. | electroless plating technique |
| D. | electroplating technique |
| Answer» C. electroless plating technique | |
| Explanation: in electroless plating, a metal ion in solution is reduced to the free metal and deposited as a metallic coating without the use of a coating without the use of an electric current. thus, this process is used in plating on glass, ceramic and plastic. | |
| 73. |
Electroplating technique is suitable for |
| A. | making conduction films ceramic |
| B. | coating with considerable thickness |
| C. | coating without use of electric current |
| D. | making conduction films of gold or copper |
| Answer» D. making conduction films of gold or copper | |
| Explanation: electroplating is a process of coating an object with one or more layers of different metal. when dc is passed through the electrolytic solution, the positive metal ions migrate from anode (metal) and deposit on the cathode (substrate). | |
| 74. |
Which of the following process is involve in thick film technology |
| A. | screen printing |
| B. | ceramic firing |
| C. | silk screening |
| D. | all of the mentioned |
| Answer» C. silk screening | |
| Explanation: silk screening is one of the processes of thin film technology. | |
| 75. |
An ancient process used till today for production of circuit films is, |
| A. | silk screening technique |
| B. | surface mount technology |
| C. | ceramic printing technique |
| D. | screen printing technique |
| Answer» D. screen printing technique | |
| Explanation: 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. | |
| 76. |
What is the advantage of using Surface Mount Technology? |
| A. | all of the mentioned |
| B. | low power consumption |
| C. | reduces heat dissipation in components |
| D. | use leaded or leadless components |
| Answer» D. use leaded or leadless components | |
| Explanation: 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. | |
| 77. |
Which of the following is an example of top- down approach for the preparation of nanomaterials? |
| A. | gas phase agglomeration |
| B. | molecular self-assembly |
| C. | mechanical grinding |
| D. | molecular beam epitaxy |
| Answer» C. mechanical grinding | |
| Explanation: 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. | |
| 78. |
Which of the following is an example of bottom-up approach for the preparation of nanomaterials? |
| A. | etching |
| B. | dip pen nano-lithography |
| C. | lithography |
| D. | erosion |
| Answer» B. dip pen nano-lithography | |
| Explanation: 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. | |
| 79. |
The properties like melting point, solubility, color, etc changes on varying the |
| A. | size |
| B. | composition |
| C. | surface properties |
| D. | none of the mentioned |
| Answer» A. size | |
| Explanation: 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. | |
| 80. |
The properties like dispersibility, conductivity, etc changes on varying the |
| A. | size |
| B. | composition |
| C. | surface properties |
| D. | none of the mentioned |
| Answer» C. surface properties | |
| Explanation: 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. | |
| 81. |
Quantum confinement results in |
| A. | energy gap in semiconductor is proportional to the inverse of the square root of the size |
| B. | energy gap in semiconductor is proportional to the inverse of the size |
| C. | energy gap in semiconductor is proportional to the square of size |
| D. | energy gap in semiconductor is proportional to the inverse of the square of size |
| Answer» D. energy gap in semiconductor is proportional to the inverse of the square of size | |
| Explanation: 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. | |
| 82. |
Which of the following is the principal factor which causes the properties of nanomaterials to differ significantly from other materials? |
| A. | size distribution |
| B. | specific surface feature |
| C. | quantum size effects |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: 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. | |
| 83. |
Select the incorrect statement from the following options. |
| A. | self-assembly is a top-down manufacturing technique |
| B. | in self-assembly, weak interactions play very important role |
| C. | self-assembling molecules adopt an organised structure which is thermodynamically more stable than the single, unassembled components |
| D. | compared to the isolated components, the self-assembled structure has a higher order |
| Answer» A. self-assembly is a top-down manufacturing technique | |
| Explanation: 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 | |
| 84. |
Which of the following is the application of nanotechnology to food science and technology? |
| A. | agriculture |
| B. | food safety and biosecurity |
| C. | product development |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the application of nanotechnology to food science and technology are agriculture, food safety and biosecurity, product development, food processing and ingredient technologies. | |
| 85. |
What are the advantages of nano-composite packages? |
| A. | lighter and biodegradable |
| B. | enhanced thermal stability, conductivity and mechanical strength |
| C. | gas barrier properties |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the advantages of nano- composite packages are-lighter and biodegradable, enhanced thermal stability, conductivity, mechanical strength and gas barrier properties. | |
| 86. |
The efficiency of today’s best solar cell is about |
| A. | 15-20% |
| B. | 40% |
| C. | 50% |
| D. | 75% |
| Answer» B. 40% | |
| Explanation: 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. | |
| 87. |
The configuration of Buckminsterfullerene is |
| A. | 12 hexagons and 22 pentagons |
| B. | 18 hexagons and 15 pentagon |
| C. | 20 hexagon and 12 pentagon |
| D. | 15 hexagon and 15 pentagon |
| Answer» C. 20 hexagon and 12 pentagon | |
| Explanation: buckminsterfullerene, commonly known as fullerene, consists of 20 hexagons and 12 pentagons, which are arrayed such that no two pentagons share a common side. | |
| 88. |
C60 is soluble in |
| A. | water |
| B. | ammonia |
| C. | hcl |
| D. | benzene |
| Answer» D. benzene | |
| Explanation: 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. | |
| 89. |
CNTs stands for |
| A. | carbon nanotubes |
| B. | carbon nanotechnology |
| C. | carbon nanoscience and technology |
| D. | carbon nine technology |
| Answer» A. carbon nanotubes | |
| Explanation: carbon nanotubes, cnts, are nanostructures with large application potential. its structure consists of a single sheet of graphite rolled into a tube. | |
| 90. |
CNTs are capped on both ends with which carbon nanostructure? |
| A. | graphite |
| B. | diamond |
| C. | c60 |
| D. | benzene |
| Answer» C. c60 | |
| Explanation: 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. | |
| 91. |
The metallic tubes have which kind of structure? |
| A. | armchair |
| B. | chiral |
| C. | boat |
| D. | achiral |
| Answer» A. armchair | |
| Explanation: 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. | |
| 92. |
The carbon tubes have high conductivity. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: 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. | |
| 93. |
Carbon nanotubes display magnetoresistance at low temperature. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: 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. | |
| 94. |
Identify the process. |
| A. | synthesis of c60 |
| B. | synthesis of cnts |
| C. | chemical vapour deposition |
| D. | carbon discharge |
| Answer» B. synthesis of cnts | |
| Explanation: 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. | |
| 95. |
The main purpose of CNTs in fuel cells is |
| A. | production of energy |
| B. | active medium |
| C. | catalyst |
| D. | storage |
| Answer» D. storage | |
| Explanation: carbon nanotubes are useful in | |
| 96. |
The figure shows a FET using CNT. Identify CNT. |
| A. | bucky balls |
| B. | soccer balls |
| C. | cricket balls |
| D. | tennis balls |
| Answer» A. bucky balls | |
| Explanation: spherical fullerenes are otherwise called as the bucky balls. they resemble to the | |
| 97. |
The fullerenes are composed with |
| A. | graphene sheets |
| B. | graphite |
| C. | lead |
| D. | other carbon materials |
| Answer» A. graphene sheets | |
| Explanation: 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. | |
| 98. |
In fullerenes, the graphene sheets are linked with |
| A. | hexagonal rings |
| B. | octagonal rings |
| C. | trigonal rings |
| D. | decagonal rings |
| Answer» A. hexagonal rings | |
| Explanation: 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. | |
| 99. |
The smallest bucky ball cluster is |
| A. | c6 |
| B. | c8 |
| C. | c10 |
| D. | c20 |
| Answer» D. c20 | |
| Explanation: the smallest bucky ball cluster is | |
| 100. |
Hollow tubes of very small dimensions are called as |
| A. | mega tubes |
| B. | carbon nano tubes |
| C. | bucky ball clusters |
| D. | polymers |
| Answer» B. carbon nano tubes | |
| Explanation: hallow tubes of very small dimensions are called the carbon nano tubes having single or multiple walls. potential applications are in electronic industry. | |
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