Description : If the ore impurities is (A) Clay, lime stone is used as flux (B) Lime stone, clay is used as flux (C) Quartz, lime stone and argillaceous iron ores are used as flux (D) All the above
Last Answer : Answer: Option D
Description : Hydraulic lime is obtained by (A) Burning of lime stone (B) Burning of kankar (C) Adding water to quick lime (D) Calcination of pure clay
Last Answer : Answer: Option B
Description : Calcareous and argillaceous materials used in manufacture of cement consists of (a) Lime stone (b) Chalk (c) Shales (d) All the above
Last Answer : (d) All the above
Description : Quick lime (or caustic lime) (A) Is obtained by the calcination of pure lime stone (B) Has great affinity to moisture (C) Is amorphous (D) All the above
Description : Three basic raw materials which are needed in large quantities for production of steel are (A) Iron ore, coal and sulphur (B) Iron ore, carbon and sulphur (C) Iron ore, coal and lime stone (D) Iron ore, carbon and lime stone
Last Answer : Answer: Option C
Description : The operation of removal of impurities or clay adhering to iron ores, is known as (A) Dressing (B) Calcination (C) Roasting (D) Smelti
Last Answer : Answer: Option A
Description : The fire clay contains pure (A) Lime (B) Oxide of iron (C) Hydrated aluminium silicate (D) Magnesium
Description : Pick up the correct statement from the following: (A) Roasting is not necessary if iron ore is an oxide (B) Impurities float on the molten iron as slag (C) The slag contains lime about 45% (D) All the above
Description : What happens when lime stone is not added during the extraction of iron?
Last Answer : If limestone is not added to charge during the extraction of iron, the blast furnace will get blocked.
Description : State the role of lime stone in the extraction of iron from haematite. Or Why is lime stone added during the extraction of iron?
Last Answer : Limestone reacts with the sand present as impurity in the ore forming calcium silicate which is taken out of the blast furnace as slag.
Description : The rocks in which argil (or clay) predominates, are called (A) Siliceous rocks (B) Argillaceous rocks (C) Calcareous rocks (D) Igneous rocks
Description : The rocks having alumina or clay as their major constituents are known as (A) Siliceous rocks (B) Argillaceous rocks (C) Calcareous rocks (D) Sedimentary rocks
Description : Ordinary Portland cement is manufactured from (A) Lime stone and clay (B) Gypsum and lime (C) Pozzolana (D) Lime, pozzolana and clay
Description : Pick up the correct statement from the following: (A) Quick lime is obtained by burning pure lime stone (B) Hydraulic lime is obtained by burning lime stone containing clay 5% to 30% (C) Poor lime is obtained by burning lime stone containing impurities more than 5% (D) All the above
Description : Pick up the correct statement from the following: (A) The heating of a material to redness in contact with air, is known as calcination (B) The property of lime by which it sets or hardens in ... (C) The product that remains after calcination of limestone, is called lime (D) All the above
Description : __________ is used as a flux in the smelting of copper ore like chalcopyrite. (A) Coke breeze (B) Lime powder (C) Silica/quartz (D) Dolomite
Last Answer : (C) Silica/quartz
Description : Which mineral is mostly found in northern and western mountains of Pakistan? A. Chromite B. Lime-stone C. China Clay D. Gypsum
Last Answer : ANSWER: B
Description : Hyderabad has deposits of _____. A. Chromite B. Gypsum C. Fire Clay D. Lime-stone
Last Answer : ANSWER: D
Description : Minerals Hyderabad has deposits of _____. A. Chromite B. Gypsum C. Fire Clay D. Lime-stone
Description : Pavement is said to be flexible if it contains (A) Water bound macadam surface (B) Stabilised soil base constructed of lime cement or tar (C) Bitumen-bound stone layer of varying aggregates (D) All the above
Description : Dolomite is a lime stone which contains carbonate of magnesia upto (A) 15 % (B) 20 % (C) 25 % (D) 45 %
Description : Which of the following pairs gives a correct combination of the useful and harmful constituents respectively of a good brick earth? (A) Lime stone and alumina (B) Silica and alkalies (C) Alumina and iron (D) Alkalies and magnesium
Description : Calcination of limestone to produce lime is done in a __________ kiln. (A) Tunnel (B) Rotary (C) Vertical shaft (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Calcination of gypsum produces (A) Plaster of Paris (B) Salt cake (C) Nitre cake (D) Lime
Last Answer : (A) Plaster of Paris
Description : Calcination of limestone is not done in a __________ kiln for producing lime. (A) Vertical shaft (B) Rotary (C) Fluidised bed (D) Fixed bed
Last Answer : (D) Fixed bed
Description : How many of the following statement is /are ture for calcination of metal ore ?
Last Answer : How many of the following statement is /are ture for calcination of metal ore ? A. (i) It makes ... of crystlliation D. Impurities of S,As and Sb are
Description : Heating of a ore below its melting point in the absence of air is known as – (1) Refining (2) Calcination (3) Roasting (4) Smelting
Last Answer : (2) Calcination Explanation: Calcination involves simple decomposition of ore on heating below its melting point usually in absence of air to produce new compounds having higher percentage of ... as removing the moisture, organic matter and volatile impurities. Calcination makes the ore porous.
Description : Sulphur removal by heating of pyrite ore in presence of air is called its (A) Reduction (B) Roasting (C) Calcination (D) Smelting
Last Answer : (B) Roasting
Description : Heating of a ore below its melting point in the absence of air is known as (1) Refining (2) Calcination (3) Roasting (4) Smelting
Last Answer : Calcination
Description : Cast iron contains phosphorus as impurity. In Bessemerisation of this cast iron the slag formed is
Last Answer : Cast iron contains phosphorus as impurity. In Bessemerisation of this cast iron the slag formed is A. `FePO_(4)` B. ` ... (4)` D. `Zn_(3)(PO_(4))_(2)`
Description : Why lime stone is added in the extraction of lead from galena ?
Last Answer : Why lime stone is added in the extraction of lead from galena ? A. It prevents the formation of ... moves the impurity of iron oxide as fusible slag.
Description : Why lime stone is added in the extraction of lead from galena?
Last Answer : Why lime stone is added in the extraction of lead from galena? A. It prevents the formation of ... moves the impurity of iron oxide as fusible slag.
Description : Which of the following ingredient of cement when added in excess quantity, causes the cement to set slowly. (a) Lime (b) Silica (c) Alumina (d) Iron oxide
Last Answer : Lime is a common ingredient in cement. It is typically added in small amounts to help the cement set more quickly. Adding too much lime can cause the cement to set slowly. Alumina, silica, and iron oxide are also common ingredients in cement, but they do not have an effect on the setting time.
Description : Pig iron is manufactured from the ores by (A) Dressing (B) Calcination and roasting (C) Smelting (D) All the above
Description : Calcination of iron ores is done (A) To remove moisture (B) To remove carbonic acid (C) By roasting in heaps (D) All the above
Description : The magnetic impurity present in cassiterite ore is
Last Answer : The magnetic impurity present in cassiterite ore is A. Silica B. Wolframite C. `SnO_(2)` D. Clay
Description : The impurity present in the ore?
Last Answer : Gangue
Description : __________ is used as a flux in the extraction of iron from iron ore (haematite) in blast furnace. (A) Bauxite (B) Limestone (C) Quartz (D) Manganese
Last Answer : (B) Limestone
Description : The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All the above
Description : The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All these
Description : White cement contains less amount of ___________ [ A ] Lime [ B ] Silica [ C ] Alumina [ D ] Iron oxide
Last Answer : [ D ] Iron oxide
Description : 'Pneumoconiosis' is a disease caused by the inhalation of __________ dust. (A) Coal (B) Uranium ore (C) Iron ore (D) Lime
Last Answer : (A) Coal
Description : Which of the following if present in iron ore, enhances its value? (A) Alumina (B) Alkali oxide (C) Lime & Magnesia (D) None of these
Last Answer : C) Lime & Magnesia
Description : Slump test is done for (A) Clay (B) Sand (C) Lime (D) Concrete
Description : The main constituent which imparts hydraulicity to hydraulic lime is (A) Calcium oxide (B) Silica (C) Clay (D) Water
Description : In the extraction of iron from haematitie, the charge used is haematite, coke and lime stone in the following weight ration
Last Answer : In the extraction of iron from haematitie, the charge used is haematite, coke and lime stone in the following weight ration ... C. `8:1:4` D. `1:4:8`
Description : In n type semi conductor added impurity is (A) pentavalent. (B) divalent. (C) tetravalent. (D) trivalent.
Last Answer : (A) pentavalent.
Description : Explain types of impurity added in a semiconductor with one example each.
Last Answer : There are two types of impurities added in a intrinsic semiconductor which are as follows 1.Donor Impurity 2.Acceptor Impurity 1.Donor Impurity - These are pentavalent which means they have five ... called as Acceptor doping. It is used to manufacture P-type semiconductor Eg:Boron,Gallium,Indium
Description : Impurity atoms to be added to pure silicon in order to make a p-type semiconductor belongs to (a) Phosphorous (b) Boron (c) Antimony (d) Aluminium
Last Answer : Boron , a group three element.