MCQOPTIONS
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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 551. |
Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ C. |
| A. | 250 |
| B. | 650 |
| C. | 850 |
| D. | 1000 |
| Answer» C. 850 | |
| 552. |
Ostwald charts are meant for |
| A. | computing the excess/deficiency of combustion air. |
| B. | calculation of flue gas temperature. |
| C. | computation of flue gas analysis. |
| D. | none of these. |
| Answer» B. calculation of flue gas temperature. | |
| 553. |
__________ tubes are good substitude for human blood vessels onrheart by-pass operation. |
| A. | PVC |
| B. | Polythene |
| C. | Teflon/dacron |
| D. | Polystyrene |
| Answer» D. Polystyrene | |
| 554. |
In a cross linked polymer, the monomeric units are linked together to constitute a three dimensional network. Which of the following is a cross-linked polymer ? |
| A. | Bakelite (phenol formaldehyde) |
| B. | Polyester |
| C. | Polythene |
| D. | Nylon-6 |
| Answer» B. Polyester | |
| 555. |
__________ is a homopolymer. |
| A. | Neoprene |
| B. | Bakelite |
| C. | Nylon-66 |
| D. | Terylene |
| Answer» B. Bakelite | |
| 556. |
Condensation polymerisation is not involved in the manufacture of |
| A. | teflon |
| B. | polythene |
| C. | terylene |
| D. | nylon |
| Answer» C. terylene | |
| 557. |
Lower temperature and large excess of ammonia in urea melt |
| A. | increases biuret formation |
| B. | decreases biuret formation |
| C. | is undersirable |
| D. | does not effect biuret formation |
| Answer» C. is undersirable | |
| 558. |
Use of catalyst is a must in the ammonia manufacture, because the reaction is reversible as well as the heat of dissociation of N2 & H2 is high. The presence of promoter along with the catalyst helps in __________ of the catalyst. |
| A. | stabilisation |
| B. | increasing the effectiveness |
| C. | improving the strength & heat resistance |
| D. | all a, b & c |
| Answer» E. | |
| 559. |
Ammonium sulphate can be produced by reacting gypsum with |
| A. | ammonia |
| B. | ammonium carbonate |
| C. | nitric acid |
| D. | none of these |
| Answer» C. nitric acid | |
| 560. |
Outer combustion chamber of blast furnace stove is lined with __________ bricks. |
| A. | fireclay |
| B. | silica |
| C. | chrome magnesite |
| D. | zirconia |
| Answer» B. silica | |
| 561. |
Fireclay bricks are used in the |
| A. | coke ovens regenerator. |
| B. | outer lining of L.D. converter. |
| C. | hearth bottom of blast furnace. |
| D. | coke oven walls. |
| Answer» B. outer lining of L.D. converter. | |
| 562. |
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of |
| A. | segar cones. |
| B. | muffles for muffle furnaces. |
| C. | insulating bricks. |
| D. | crucibles used for melting of high purity metals. |
| Answer» E. | |
| 563. |
Ferromagnetic ceramic material is not used in the |
| A. | thermal insulation |
| B. | transformers |
| C. | magnetic switches |
| D. | television sets |
| Answer» B. transformers | |
| 564. |
Cold crushing strength of a refractory does not depend upon its |
| A. | shape |
| B. | composition |
| C. | firing temperature |
| D. | texture |
| Answer» B. composition | |
| 565. |
Epoxy resin is a polymer containing two or more groups called epoxide group or ethoxyline group. It is a |
| A. | polyamide & an elastomer. |
| B. | good adhesive. |
| C. | surface coating agent. |
| D. | both (b) and (c). |
| Answer» E. | |
| 566. |
Cermets are |
| A. | composite material containing both ceramic & metallic constituents. |
| B. | having high strength & resistance to high temperature. |
| C. | used in space vehicles, missiles & nuclear energy plants. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 567. |
Fusion temperature of pure silica (SiO2) is __________ C. |
| A. | 1350 |
| B. | 1715 |
| C. | 2570 |
| D. | 2800 |
| Answer» C. 2570 | |
| 568. |
Thermosetting polymers as compared to thermoplastic polymers |
| A. | are formed by addition polymerisation. |
| B. | have three dimensional structure. |
| C. | have linear structure. |
| D. | none of these. |
| Answer» C. have linear structure. | |
| 569. |
Silliminite (Al2O3.SiO2) refractory, which is a neutral refractory, is not used in |
| A. | pottery furnace |
| B. | glass melting furnace |
| C. | crucibles |
| D. | gas retorts |
| Answer» E. | |
| 570. |
Silica bricks are never used for lining the |
| A. | beehive coke ovens. |
| B. | by-product coke ovens. |
| C. | dome of blast furnace stoves. |
| D. | roof of open hearth furnace. |
| Answer» B. by-product coke ovens. | |
| 571. |
Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to |
| A. | thermal spalling |
| B. | slag attack |
| C. | fusion under load |
| D. | CO attack |
| Answer» B. slag attack | |
| 572. |
Fireclay refractories |
| A. | are not resistant to the action of basic slags. |
| B. | combine with salts (e.g. chlorides sulphates etc.) & bases (e.g. lime, magnesia etc.) forming fusible aluminates silicates etc. |
| C. | shrink during firing |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 573. |
Which is a neutral refractory ? |
| A. | Graphite |
| B. | Magnesite chrome |
| C. | Silica |
| D. | Magnesia |
| Answer» B. Magnesite chrome | |
| 574. |
Mixing of ground refractory material and water is done in a __________ mill. |
| A. | pug |
| B. | ball |
| C. | tube |
| D. | rod |
| Answer» B. ball | |
| 575. |
Chrome magnesite bricks are |
| A. | acidic in nature. |
| B. | neutral in nature. |
| C. | having higher RUL than silica bricks. |
| D. | made by mixing 30% chromite and 70% periclase. |
| Answer» D. made by mixing 30% chromite and 70% periclase. | |
| 576. |
Colour of fireclay bricks is |
| A. | light buff to reddish buff |
| B. | yellow |
| C. | black |
| D. | none of these |
| Answer» B. yellow | |
| 577. |
Refractory castables are used for |
| A. | producing monolithic linings. |
| B. | patch work. |
| C. | minimising the number of joints in the structure. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 578. |
Because of its very high refractoriness of the order of __________ C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns. |
| A. | 1800 |
| B. | 2200 |
| C. | 2400 |
| D. | 2700 |
| Answer» E. | |
| 579. |
Mass of a positron is same as that of a/an |
| A. | electron |
| B. | -particle |
| C. | proton |
| D. | neutron |
| Answer» B. -particle | |
| 580. |
Heavy water has maximum density at __________ C. |
| A. | 4 |
| B. | 11.6 |
| C. | 0 |
| D. | 18.6 |
| Answer» C. 0 | |
| 581. |
Uranium percentage in monazite sand is about |
| A. | 0.01 |
| B. | 0.25 |
| C. | 1.2 |
| D. | 7 |
| Answer» C. 1.2 | |
| 582. |
Artificially produced radioactive isotopes are used for |
| A. | power generation. |
| B. | treatment of certain diseases. |
| C. | initiating nuclear fission and fusion. |
| D. | all (a), (b) and (c). |
| Answer» C. initiating nuclear fission and fusion. | |
| 583. |
Benzoyl chloride is not used as a catalyst in the manufacture of |
| A. | polystyrene |
| B. | polyvinyl acetate |
| C. | polypropylene |
| D. | polyvinyl chloride-co-vinylacetate |
| Answer» D. polyvinyl chloride-co-vinylacetate | |
| 584. |
Polycaprolactum is also known as |
| A. | nylon-66 |
| B. | nylon-6 |
| C. | teflon |
| D. | SBR |
| Answer» C. teflon | |
| 585. |
The conversion of caprolactum in the above case is about __________ percent. |
| A. | 25 |
| B. | 50 |
| C. | 70 |
| D. | 90 |
| Answer» E. | |
| 586. |
Bakelite is a/an |
| A. | addition polymer |
| B. | elastomer |
| C. | thermoplastic |
| D. | none of these |
| Answer» E. | |
| 587. |
__________ scrap can be recycled & reutilised. |
| A. | Bakelite |
| B. | Epoxy resin |
| C. | Polythene |
| D. | none of these |
| Answer» D. none of these | |
| 588. |
Ebonite is a/an |
| A. | highly vulcanised rubber. |
| B. | natural rubber. |
| C. | unvulcanised raw rubber. |
| D. | adhesive. |
| Answer» B. natural rubber. | |
| 589. |
Which of the following additives are added to plastics to make it impervious to X-rays ? |
| A. | Asbestos |
| B. | Barium salt |
| C. | Carborundum |
| D. | Phthalic acid |
| Answer» C. Carborundum | |
| 590. |
Paper like thin plastic articles can be produced by |
| A. | blow moulding |
| B. | vacuum thermo forming |
| C. | injection moulding |
| D. | none of these |
| Answer» C. injection moulding | |
| 591. |
Addition polymerisation takes place either by a free radical mechanism or ionic machanism depending on the reagents used. Free radical polymerisation is catelyzed by __________ , which decompose to give free radicals. |
| A. | organic peroxides |
| B. | sulphuric acid |
| C. | hydroflouric acid |
| D. | none of these |
| Answer» B. sulphuric acid | |
| 592. |
__________ is produced by polymerisation of chloroprene. |
| A. | Thiokol (a polysulphide rubber) |
| B. | Butyl rubber |
| C. | Neoprene |
| D. | Polyurathane rubber |
| Answer» D. Polyurathane rubber | |
| 593. |
Pick out the wrong statement regarding the solubility characteristics of high polymers. |
| A. | Greater the degree of cross-linking in the polymer, lesser is its solubility. |
| B. | Polymers having more aliphatic character are more soluble in aliphatic solvents, while those polymers having more aromatic character are more soluble in aromatic solvents. |
| C. | Swelling tendency or solubility of polymers in a particular solvent decreases with increase in molecular weight of the solvent. |
| D. | High molecul ar weight polymers on dissolving gives solution of very low viscosity. |
| Answer» E. | |
| 594. |
Flexible plastic pipes are made of |
| A. | high density polyethylene (HDPE). |
| B. | low density polyethylene (LDPE). |
| C. | polypropylene. |
| D. | unsaturated polyester. |
| Answer» C. polypropylene. | |
| 595. |
Main constituent of natural rubber is |
| A. | polystyrene |
| B. | polyisoprene |
| C. | polybutadiene |
| D. | poly chloroprene |
| Answer» C. polybutadiene | |
| 596. |
The monomer of natural rubber is |
| A. | DMT |
| B. | isoprene |
| C. | 2 methyl-1-propene |
| D. | both (b) and (c) |
| Answer» E. | |
| 597. |
In case of dry spinning of polymers, the polymer solution in a volatile solvent is forced through the spinnerates into a warm air chamber, where the solvent evaporates leaving behind the polymer in the filament form. Dry spinning is used for __________ fibres. |
| A. | polythene |
| B. | PVC |
| C. | rayon |
| D. | polyvinyl acetate |
| Answer» C. rayon | |
| 598. |
The major component of acrylic fibres is |
| A. | polyamides |
| B. | polyolefins |
| C. | polyacrylonitrile |
| D. | polyesters |
| Answer» D. polyesters | |
| 599. |
Which of the following polymers is used for making a non stick coating on frying pans ? |
| A. | Bakelite |
| B. | Teflon |
| C. | Perspex |
| D. | PVC |
| Answer» C. Perspex | |
| 600. |
Which of the following polymers does not belong to the class of polyacrylate polymer ? |
| A. | PMMA |
| B. | Polyacrylonitrile |
| C. | Polyethyl acrylate |
| D. | None of these |
| Answer» E. | |