15251. Which of the following processes follows the hardening process for reducing the hardening strains & increasing the toughness of the steel part?
15252. Heat required to raise the temperature of a body by 1 °C is called its
15253. Coating of zinc over steel is known as
15254. Air-petrol ratio in an automotive petrol engine is around
15255. The property of material, by which a given amount of energy is absorbed by it, without plastic deformation is called
15256. Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode
15257. Electrochemical corrosion can occur, only if __________ is present in contact with metal.
15258. Crystallisation of polymers is an undesirable property. Crystallisation of celluloid is prevented by adding
15259. Preheating prior to welding is done for the purpose of
15260. Presence of sulphur in steel reduces the
15261. Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother?
15262. Otto cycle used in spark ignition petrol engines is also known as the constant __________ cycle.
15263. Fire on fuel oil lines can be extinguished by
15264. In a furnace with heating element temperature at 1700°C, the dominant machanism of heat transfer will be
15265. Optical activity is a/an __________ property.
15266. Solution loss reaction occurs
15267. Out of the following materials, the one which generally exhibits an yield point is
15268. The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 - T2)/T1. The co-efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2 is given by
15269. Diamagnetic materials
15270. In connection with corrosion of metals, passivation is the process that
15271. With increase in impurities in metals, their corrosion resistances
15272. Most important property of steels for use in automobile bodies is the
15273. Consideration of the creep is the most important in case of the
15274. Non-ferrous alloys used for making cutting tools need not have high
15275. Hollow shafts can be made as strong as solid shafts by making the twisting moments of both the shafts same. Shafts made by __________ have residual stresses.
15276. Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be
15277. Glycerene is used as a coolant in cooling of some engines instead of water, because
15278. Cold working of a material results in increase in hardness, which is termed as the __________ hardening.
15279. Potable water means the water used for
15280. One ton of refrigeration is not equivalent to the heat removal rate of
15281. Starting friction is low in case of the __________ lubrication.
15282. Ultimate strength in tension as compared to that in shear for steel is
15283. Which of the following heat treatment processes is usually applied to castings ?
15284. Photographic plates are coated with
15285. Hardening of steel is not possible, unless it is heated __________ critical point.
15286. Isotropic materials have the same __________ in all directions.
15287. The most important requirement for aluminium industry is the availability of cheap
15288. Spheriodising of a material is a/an __________ process.
15289. The trace metal present in insulin is
15290. Cold cracking in the heat affected zone of a high strength steel weld can take place because of the
15291. Drossing is a __________ operation.
15292. Most of the phosphorous present in the blast furnace burden enters into
15293. During sensible heating of humid air
15294. Iron content in Indian iron ore is about __________ percent.
15295. The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is
15296. __________ of hard alloy and tool steel is done to make it easily machinable.
15297. Which of the following mainly decides the current to be employed is arc welding ?
15298. Temperature attained in soldering of metals is about __________ °C.
15299. The normal stress is the same in all directions at a point in a fluid, only when the fluid
15300. A 2 kg object weighs 1.8 kgf on a spring balance. The value of 'g' at that location in m/sec2 is