A. Graphite
B. Lead sulphide
C. Lead
D. Both B. & C.
Correct Answer: Graphite ✔
Last Updated: February 10, 2019
Related MCQs
- Hot dipping process is used for coating a low melting point metal (e.g. Pb, Sn, Zn) on iron, steel & copper having relatively higher melting points. Which of the following is not a hot dipping process ?
- The underground well of a bio gas plant is called the__________?
- A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm2 ?
- Water hammer is caused in steam carrying pipelines, because of __________?
- In the diving apparatus, helium is used along with oxygen, because it is __________?
- Probability of cavitation occuring becomes very high, when the local __________ resulting ?
- The approximate height of a blast furnace having a useful volume of 2000 m3 is about __________ metres ?
- Photographic plates are coated with __________?
- Air/fuel ratio by weight for combustion of methane with theoretical quantity of air will be about __________?
- Which of the following gases cause global warming ?
- Potable water means the water used for__________?
- Softening of hardened steel is done by its__________?
- Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the__________?
- Cold working of a material results in increase in hardness, which is termed as the __________ hardening ?
- __________ glass is used in the mercury in glass thermometer meant for measuring a temperature of 500°C ?
- Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity) __________?
- During sensible heating of humid air__________?
- During sensible cooling of air, its wet bulb temperature ?
- Function of gear box is to__________?
- Carbon supply in pack carburising process is in the form of __________?
- Heat release during phase change is observed in case of a/an__________?
- Steam condenser tubes are made of admiralty brass, in which percentage of zinc & copper are __________ respectively ?
- 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 ?
- The excess air required for the combustion of pulverized coal is of the order of about __________ percent ?
- The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the __________ of a boiler ?
- Thermal conductivity of a material does not depend upon its__________?
- The type of pump used for lifting large quantity of sewage is a __________ pump ?
- Coating provided on the electrodes used in the arc welding is not expected to__________?
- Non-ferrous alloys used for making cutting tools need not have high__________?
- Transformer cores are normally made from __________?
- Pearlite comprises of__________?
- Spheroidising of a material is a/an __________ process?
- __________ number determines whether the fluid flow in an open channel is super-critical, critical or sub-critical ?
- Satellite is a __________ material?
- Catalyst used in the catalytic converter employed in automobiles to convert CO into CO2 and for complete oxidation of un-burnt hydrocarbons is__________?
- Cascade control is__________?
- For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = – 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be__________?
- Hardening of steel is not possible, unless it is heated __________ critical point ?
- Strain hardening effect in metals subjected to cold working is due to the __________ mechanism?
- Atomic __________ of an element is a whole number ?
- Which of the following heat treatment processes is usually applied to castings ?
- A material is capable of resisting softening at high temperature, because of its property termed as__________?
- When an isolated thermodynamic system executes a process __________?
- The main constituent of bones is __________?
- Which of the following alloying elements is present in maximum percentage in high speed steel ?
- Baffles provided on the shell side of a shell and tube heat exchanger are meant for __________?
- While the bin cards are used in the effective stores management, the queuing theory is associated with the __________ time ?
- __________ iron is produced by the annealing of white cast iron?
- With increase in impurities in metals, their corrosion resistances__________?
- In the blast furnace, incorporation of water vapour in the blast gives the following effect ?
- The product out from a cupola is called __________?