Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode
(A) Occurs higher in the electro-chemical series of metals
(B) Is exemplified by magnesium plate
(C) Is much cheaper than the cathodic base material to be guarded against corrosion
(D) All (A), (B) & (C)

1 Answer

Answer :

(D) All (A), (B) & (C)

Related questions

Description : Anodic material used for the cathodic protection of underground buried steel pipeline is (A) Nickel or copper (B) Zinc or magnesium (C) Bronze (D) Brass

Last Answer : (B) Zinc or magnesium

Description : Impressed current cathodic protection is used on vessels instead of _________________. A. fire alarm systems B. repeated painting C. sacrificial zincs D. vacuum tube degaussing systems

Last Answer : Answer: C

Description : Pick out the wrong statement about coating/electroplating of metals. (A) Phosphate coating is used as an excellent base for paints & enamels (B) Phosphate coating is less corrosion resistant than ... coating metal is made the anode (D) Calorising is the process of coating steel with chromium

Last Answer : (D) Calorising is the process of coating steel with chromium

Description : Which of the following metals in not used for coating of the base metal to guard it against corrosion? (A) Lead (B) Cadmium (C) Magnesium (D) Aluminium

Last Answer : (C) Magnesium

Description : Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its (A) Lower cost (B) Abundant availability (C) Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry (D) None of these

Last Answer : (C) Resistance to vegetable acids as the tin plate are commercially used in 'canning' industry

Description : In an impressed current cathodic protection system, the anode is ____________. A. connected to the hull and deteriorates with time B. insulated from the hull and does not waste away C. connected to the hull but does not waste away D. insulated from the hull but deteriorates with time

Last Answer : Answer: B

Description : Galvanic corrosion cannot be prevented by (A) Cathodic protection (B) Anodic protection (C) Usage of largest possible anodic area (D) Any one of these

Last Answer : Option B

Description : The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's ... the presence of salt air D. maintain a minimum constant alternator load to prevent overheating

Last Answer : Answer: A

Description : Galvanising (i.e., zinc coating) of steel sheets is done to (A) Prevent its rusting by contact with corrosive atmosphere (B) Protect the base metal by cathodic protection (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Description : Lead is (A) Not resistant to corrosion (B) Used as a cathodic material (C) Not used as pigment (in its compound forms) for paints (D) Used as a shock absorber (in mattress form) between the foundation and steel framework of skyscraper buildings

Last Answer : (D) Used as a shock absorber (in mattress form) between the foundation and steel framework of skyscraper buildings

Description : Zinc is not used (A) For producing zinc base die casting alloys (B) In its oxide form as pigments (C) As anode for corrosion prevention in boiler (D) As an alloying element in various bronzes

Last Answer : (D) As an alloying element in various bronzes

Description : Corrosion of a metal occurs at the (a) Anode (b) Cathode (c) Both anode and cathode (d) None of the above

Last Answer : Ans:(a)

Description : Metalloids (A) Are good conductor of heat & electricity (B) Act as electron donors with metals & as electron acceptor with non metals (C) Are not necessarily solids at room temperature ... & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron

Last Answer : D) Are compounds that exhibit both metallic & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron

Description : Write any two examples of sacrificial anodic protection.

Last Answer : Examples: 1) To protect buried water or gas pipelines. 2) To protect buried cables. 3) To protect hot water tank, etc. 4) Mg or Zn rods are bolted along the sides of ship, hot water ... protect open water box coolers. 6) To protect water tanks. 7) To protect transmission line towers, etc. 

Description : Describe sacrificial anodic protection with neat diagram.

Last Answer : Method: The metallic structure to be protected from corrosion is connected to anodic metal (upper placed in galvanic series) by an insulated wire. Thus externally added metal like Zn, Al, Mg, etc ... hot water tanks to prevent corrosion. The protection of underground pipelines is shown in Fig.

Description : Crude oil is transported inland from oil field to refineries, mainly by the (A) Road tankers (B) Rail tankers (C) Underground pipelines (D) None of these

Last Answer : (C) Underground pipelines

Description : (3) made cathode and a pure nickel red, the anode Explanation: Electroplating is the deposition by electrolysis of a coating of metal upon a conducting surface. The simplest system makes the object to be ... on the spoon is called reduction and, therefore, the spoon is also referred to as a cathode.

Last Answer : Which of the following is not a method of preparing oxygen? (1) Electrolysis of water (2) Fractional distillation of liquid air (3) Decomposition of potassium permanganate (4) Decomposition of manganese dioxide

Description : Which one of the following metals is immune to corrosion by air, water, hydrochloric acid and nitric acid; but is soluble in aqua regia? w) gold x) silver y) magnesium z) nickel

Last Answer : ANSWER: W -- GOLD

Description : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. Coke powder is spreadded over the molten electro

Last Answer : Electrolytic reduction of `Al_(2)O_(3)`. Electrolyte (`Al_(2)O_(3)+"cryolite")` Anode: Graphite rods. ... of molten aluminium by air D. (a) both (b)

Description : In electro-refining, the pure metal is deposited on – (1) vessel (2) electrolyte (3) cathode (4) anode

Last Answer : (3) cathode Explanation: In electro-refining, the anodes consist of unrefined impure metal, and as the current passes through the acidic electrolyte the anodes are corroded into the solution so ... pure metal onto the cathodes. Electrolytic refining is used to extract impurities from crude metals.

Description : In electro-refining, the pure metal is deposited on (1) vessel (2) electrolyte (3) cathode (4) anode

Last Answer : cathode

Description : Ceramic nuclear metals compared to solid nuclear metals have (A) Higher melting points (B) Low strength at high temperature (C) More chances of radiation damage (D) Poorer corrosion resistance

Last Answer : (A) Higher melting points

Description : The metals occuring at the lower most position in the electromotive series (A) Do not resist corrosion (B) Resist corrosion very strongly (C) Are very brittle (D) Are heat insulators

Last Answer : (B) Resist corrosion very strongly

Description : Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation ... (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

Last Answer : (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

Description : The circuit shown in the illustration represents a ________. EL-0090 A. battery charging circuit B. synchronous exciter C. depth sounding unit D. cathodic protection system

Last Answer : Answer: D

Description : The amount of current flow required for the cathodic protection of a vessel is dependent upon the _________. A. amount of bare steel surface B. speed of the ship through the water C. temperature of the water D. all of the above

Last Answer : Answer: D

Description : Explain cathodic protection. Give one example.

Last Answer : Cathodic protection: It is the method in which the metal to be protected is forced to behave as a cathode. Examples: 1) To protect buried water or gas pipelines. 2) To protect buried cables. 3) ... water box coolers. 6) To protect water tanks. 7) To protect transmission line towers, etc.  

Description : Powdery materials can be guarded against caking tendency on storage by (A) Providing irregular grain size (B) Providing minimum percentage of voids (C) Having maximum possible points of contact (D) None of these

Last Answer : (D) None of these

Description : Pick out the wrong statemen (A) Autocatalytic reactions are exemplified by microbial fermentation reactions (B) The slowest step has the greatest influence on the overall reaction rate in case of an ... reaction (D) Hydrolysis of ester in presence of alkali or acid is a zero order reaction

Last Answer : (D) Hydrolysis of ester in presence of alkali or acid is a zero order reaction

Description : What is an internal organizational Internet that is guarded against outside access by a special security feature called a firewall (which can be software, hardware, or a combination of the two)? a. Client/server network b. Intranet c. Extranet d. Thin client

Last Answer : b. Intranet

Description : Why alkali metals are highly electro positive & they are not found in free state ?

Last Answer : The loosely held s-electron in the outermost valence shell of these elements makes them the most electropositive metals. They readily lose electron to give monovalent M+ ions. Hence they are never found in free state in nature. 

Description : (3) preventing rapid setting of cement Explanation: Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, the remainder consisting of ... mixed with water by way of a complex series of chemical reactions still only partly understood.

Last Answer : Milk is a colloidal system in which: (1) Water is dispersed in fat (2) Fat is dispersed in water (3) Fat and water are dispersed in each other (4) Fat is dissolved

Description : Electrometallurgical methods of metal extraction is normally used for those metals (A) Whose oxide/ore is not reduced by carbon (B) Which fall in the category of alkali & alkaline earth metals (C) Which stands higher in the electrochemical series of the metal (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes (A) Fading of dyes on textiles (B) Corrosion, tarnishing & soiling of metals (C) Reduced strength of textiles (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Exposure to SO2 containing chimney gases results in the (A) Reduction in strength of leather & cloth (B) Acceleration of corrosion rates of metals (C) Increased drying & hardening time of paints (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Absorption accompanied with chemical reaction is exemplified by the absorption of (A) Ammonia in water (B) Benzol present in coke oven gas by wash oil (C) SO2 in alkaline solution (D) All (A), (B) and (C)

Last Answer : (C) SO2 in alkaline solution

Description : Elastomers are (A) Thermosetting material (B) Exemplified by protein derivatives (C) Having high flexural strength (D) Having very high tensile strength and heat resistance

Last Answer : (C) Having high flexural strength

Description : Tin coating on metals is not done by (A) Spraying (B) Powder metallurgy (C) Hot dipping (D) Electro-deposition

Last Answer : (B) Powder metallurgy

Description : Electro deposition of metals i.e. electroplating is never done on (A) Metals (B) Alloys (C) Refractories (D) Non-metals

Last Answer : (C) Refractories

Description : The process of moving molecules against an electro-chemical gradient is:

Last Answer : ANSWER: ACTIVE TRANSPORT

Description : The method used to produce electron emission in most vacuum tubes is known as ____________. A. photoelectric emission B. secondary electric emission C. cold cathodic electric emission D. thermionic emission

Last Answer : Answer: D

Description : Pipelines carrying various utilities in chemical industries are identified by their colour codes. The color of pipeline carrying steam is (A) Black (B) Silver grey (C) Green (D) Yellow

Last Answer : ) Silver grey

Description : Which of the following is the most widely used insulating material for steam carrying pipelines? (A) Ceramic fibre blanket (B) Glass wool and 85% magnesia (C) Vermiculite (D) Slag wool

Last Answer : (B) Glass wool and 85% magnesia

Description : Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool

Last Answer : (D) 85% magnesia cement and glass wool

Description : Stereospecific agents are exemplified by (A) Radiation (B) Supported metal oxide catalysts (C) Ziegler catalysts (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : Hastelloy C is a good material of construction in chemical process industry, since it is (A) Highly corrosion resistant and is readily fabricated (B) Relatively inexpensive although it can be ... most alkalis, particularly because of its copper content (D) Light and resists attack by acids

Last Answer : (D) Light and resists attack by acids

Description : Yield of urea can be increased with excess ammonia and higher pressure & temperature, but because of __________ this is normally not done. (A) Increased biuret formation (B) High corrosion rate (C) Increased cost of equipment (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : _____ is a surface fatigue failure which occurs when the load on the bearing part exceeds the surface endurance strength of the material. (a) Scoring (b) Pitting (c) Corrosion

Last Answer : (b) Pitting