Description : Which one of the following statements is not correct? Vulcanisation of rubber makes it - (1) soft and flexible (2) strong and hard (3) chemical resistant (4) withstand higher temperatures
Last Answer : (1) soft and flexible Explanation: In order to give more strength and more elasticity, natural rubber is heated with sulphur or sulphur compounds at 150°C temperature. Vulcanized rubber has good ... of vulcanized rubber is enhanced up to 100°C. It has good resistance to organic solvents.
Description : Which of the following statements is correct? (a) Sporopollenin can be degraded by enzymes. (b) Sporopollenin is made up of inorganic materials. (c) Sporopollenin can withstand high temperatures ... strong acids and alkalis. (d) Sporopollenin can withstand high temperatures but not strong acids.
Last Answer : (c) Sporopollenin can withstand high temperatures as well as strong acids and alkalis
Description : Vulcanisation of raw rubber makes it (A) Soft (B) Less elastic (C) Plastic (D) Tacky
Last Answer : (B) Less elastic
Description : (4) Liquid Hydrogen + Liquid Oxygen Explanation: LOX and liquid hydrogen, used in the Space Shuttle orbiter, the Centaur upper stage of the Atlas V, Saturn V upper stages, the ... to withstand high combustion pressures and temperatures and they can be regeneratively cooled by the liquid propellant.
Last Answer : The BOD values of water indicate the (1) amount of organic debris (2) amount of oxygen used for biochemical oxidation (3) amount of oxygen used for biochemical reduction (4) amount of ozone used for biochemical oxidation
Description : Which of the following precautions should be taken when troubleshooting various power circuits using a common solenoid-type mechanical voltage tester (wiggins)? A. Never use this tester on circuits greater ... voltage expected in the circuit in order to prevent damage from an off-scale reading.
Last Answer : Answer: A
Description : In vulcanisation process, rubber can be hardened by adding - (1) Nitrogen (2) Silicon (3) Sulphur (4) Alcohol
Last Answer : (3) Sulphur Explanation: In order to give more strength and more elasticity, natural rubber is heated with sulphur or sulphur compounds at 150°C temperature. Vulcanized rubber has good tensile strength.
Description : In vulcanisation process, rubber can be hardened by adding (1) Nitrogen (2) Silicon (3) Sulphur (4) Alcohol
Last Answer : Sulphur
Description : Which of the following metals is used in Space Crafts to withstand high temperatures? (1) Fe (2) Ti (3) Ni (4) Pb
Last Answer : (2) Ti Explanation: Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
Description : Which of the following metals is used in Space Crafts to withstand high temperatures ? (1) Fe (2) Ti (3) Ni (4) Pb
Last Answer : Ti
Description : In vulcanisation, with which the natural rubber is heated? -Do You Know?
Last Answer : answer:
Description : In vulcanisation of rubber,
Last Answer : In vulcanisation of rubber, A. sulphur reacts to form new compound B. sulphur cross-links are ... layer over rubber D. all the statements are correct
Description : In vulcanisation, with which the natural rubber is heated?
Description : The process involved in converting rubber into a thin sheet or coating it on fabric is called (A) Extrusion (B) Mastication (C) Calendaring (D) Vulcanisation
Last Answer : (C) Calendaring
Description : Vulcanisation of rubber does not increase its (A) Softness (B) Oxidation resistance (C) Weight & strength (D) Elasticity & water solubility
Last Answer : (A) Softness
Description : Vulcanisation of rubber does not increase its (A) Elasticity (B) Plasticity (C) Ductility (D) None of these
Last Answer : (B) Plasticity
Description : Vulcanisation of rubber (A) Decreases its tensile strength (B) Increases its ozone & oxygen reactivity (C) Increases its oil & solvent resistance (D) Converts its plasticity into elasticity
Last Answer : (D) Converts its plasticity into elasticity
Description : Peptizers like aromatic mercaptans (e.g. thiophenes) are added in rubber to (A) Protect rubber goods from attack by oxygen & ozone present in the atmosphere (B) Reduce its viscosity to ... processing (C) Reduce the time of vulcanisation and quantity of vulcanising agent (D) Increase its viscosity
Last Answer : (B) Reduce its viscosity to permit easier processing
Description : Most commonly used rubber vulcanisation agent is (A) Sulphur (B) Bromine (C) Platinum (D) Alumina
Last Answer : (A) Sulphur
Description : Vulcanisation of rubber decreases its (A) Tensile strength (B) Resistance to organic solvents (C) Tackiness (D) Working temperature range
Last Answer : (C) Tackiness
Description : Fillers such as zinc oxide and carbon black are added to the crude natural rubber before vulcanisation in order to improve its (A) Elasticity (B) Strength (C) Plasticity (D) Weathering characteristics
Last Answer : (D) Weathering characteristics
Description : __________ of rubber decreases after its vulcanisation. (A) Resistance to the action of organic solvent (B) Tackiness (C) Maximum service temperature (D) Tensile strength
Last Answer : (B) Tackiness
Description : Ceramic remunerators can withstand temperatures up to: a) 600 oC b) 1300 oC c) 1700oC d) 950oC
Last Answer : 1300 oC
Description : With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct ? (1) Increasing atmospheric CO 2 concentration up to 0.05% can enhance CO 2 fixation ... for higher yield (4) Light saturation for CO 2 fixation occurs at 10% of full sunlight
Last Answer : (2) C 3 plants respond to higher temperatures with enhanced photosynthesis while C 4 plants have much lower temperature optimum
Description : Which of the following is not property of an alloy? a) strong b)resistant to corrosion c)hard d)Poor conductor of electricity
Last Answer : d)Poor conductor of electricity
Description : The atmosphere exerts enormous pressure on us. But we do not feel it because (a) we are used to it (b) our bones are very strong and can withstand this pressure (c) the surface area of our head is very small (d) our blood exerts a pressure slightly more than that of the atmosphere
Last Answer : Ans:(d)
Description : The lintels are preferred to arches because (A) Arches require more headroom to span the openings like doors, windows etc. (B) Arches require strong abutments to withstand arch thrust (C) Arches are difficult in construction (D) All of the above
Last Answer : Answer: Option D
Description : Is rubber wood hard wood tree or soft wood tree?
Last Answer : Feel Free to Answer
Description : The group Firmicutes means _______ skin. a. soft b. strong c. hard d. rough
Last Answer : b. strong
Description : Asbestos pipes are (A) Light in weight and easy to transport (B) Highly resistant to corrosion (C) High flexible to accommodate deflection upto 12° (D) All the above
Last Answer : (D) All the above
Description : Which of the following statements regarding evacuated tube collectors (ETC) are true? i) ETC is used for high temperatures upto 150oC ii) because of use of vacuum between two concentric glass tube, higher amount of heat is ... upon the ambient temperature i & iii b) ii & iii c) i & iv d) i & ii
Last Answer : d) i & ii
Description : Flexible foam (for mattresses) are usually made of (A) PVC (B) Silicone rubber (C) Polyurethanes (D) Polyamides
Last Answer : (C) Polyurethanes
Description : Adhesive tape to affix rubber to carpet in high temperatures?
Last Answer : just glue them
Description : Solvent deoiling process is used for separating oil and soft wax from hard wax. Methyl iso-butyl ketone and methyl ethyl ketone (MEK) are two commonly used deoiling solvents. Use of former as the deoiling solvent ... nitration temperature (C) Lower solvent dilution ratio (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Sodium salt of higher molecular weight fatty acid is termed as the __________ soap. (A) Hard (B) Soft (C) Metallic (D) Lubricating
Last Answer : (B) Soft
Description : Pick out the wrong statement. (A) A ferromagnetic material becomes paramagnetic above the 'Curie temperature' (B) Permanent magnets are made of hard materials, whereas electromagnets require soft ... hysterisis loss and coercive forces (D) Tungsten steel and alnico are not hard magnetic materials
Last Answer : Option D
Description : In the absence of __________, pricing remains a flexible and convenient way to adjust the marketing mix. A) experience -curve effects B) strong price competition C) weak price competition D) government price control E) low -priced substitute products
Last Answer : D) government price control
Description : Choose the correct statement about topical NSAID preparations: A. They produce high drug levels in the blood by avoiding hepatic first pass metabolism B. They produce high drug levels in ... a strong placebo effect D. Interindividual variability in clinical response to these preparations is minimal
Last Answer : C. They elicit symptomatic relief in soft tissue rheumatism mainly by a strong placebo effect
Description : The substance that is added to make natural rubber strong and more bouncy is – (1) Polythene (2) Sponge (3) Sulphur (4) Chlorine
Last Answer : (3) Sulphur Explanation: Vulcanization is a chemical process for converting rubber or related polymers into more durable materials via the addition of sulfur or other equivalent "curatives ... individual polymer chains. Vulcanized materials are less sticky and have superior mechanical properties.
Description : The substance that is added to make natural rubber strong and more bouncy is (1) Polythene (2) Sponge (3) Sulphur (4) Chlorine
Description : Which characteristic of the Sun primarily determines the orbits of planets in our solar system A Large volume B Strong gravitational field C Mostly made of hydrogen D High surface temperatures?
Last Answer : B (gravity)
Description : If a necrotizing soft tissue infection is considered, therapy mandates: a. Empiric administration of antibiotics active against gram-positive, gram-negative, and anaerobic bacteria b. Due to usually ... is mandatory d. The use of hyperbaric oxygen has been demonstrated to be clearly advantageous
Last Answer : Answer: a, c Identification of a necrotizing, soft tissue infection mandates immediate operative intervention with aggressive resection of all involved tissues and empiric ... remains without controlled trials demonstrating any additional benefits derived from hyperbaric oxygen therapy
Description : Chilled iron castings are (A) Easily machinable (B) Soft on surface (C) Highly wear resistant (D) None of these
Last Answer : (C) Highly wear resistant
Description : Silicone rubber is not resistant to the corrosive action of (A) Sulphuric acid (10%) (B) Sulphuric acid (95%) (C) Ether (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Bakeries use yeast in bread-making because it – (1) makes the bread hard (2) makes the bread soft and spongy (3) enhances the food values (4) keeps the bread fresh
Last Answer : (2) makes the bread soft and spongy Explanation: Bread is usually made from wheat-flour dough that is cultured with yeast, allowed to rise, and finally baked in an oven. The fermentation due to yeast makes the bread soft and spongy.
Description : Bakeries use yeast in breadmaking because it (1) makes the bread hard (2) makes the bread soft and spongy (3) enhances the food values (4) keeps the bread fresh
Last Answer : makes the bread soft and spongy
Description : Consider the following statements S1 and S2 : S1 : A hard handover is one in which the channel in the source cell is retained and used for a while in parallel with the channel in the target cell. S2 : A soft handover ... and S2 is true. (C) Both S1 and S2 are true. (D) Both S1 and S2 are not true.
Last Answer : (D) Both S1 and S2 are not true.
Description : Consider the following statements 1. Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluorocarbons. 2. Ammonia can be liquefied at ambient temperatures and at low pressures. 3. Chlorofluorocarbons are ... 3 only (b) 2 and 3 only (c) 1, 2 and 3 (d) 3 only
Last Answer : Ans:(a)
Description : Three of the following statements about enzymes are correct and one is wrong. Which one is wrong? (a) Enzymes require optimum pH for maximal activity. (b) Enzymes are denatured at high temperature but ... - 90°C. (c) Enzymes are highly specific. (d) Most enzymes are proteins but some are lipids.
Last Answer : (d) Most enzymes are proteins but some are lipids.