Write any two examples of sacrificial anodic protection.

Write any two examples of sacrificial anodic protection.
by

1 Answer

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 tanks or inserted into boiler to prevent corrosion.

5) To protect open water box coolers.

6) To protect water tanks.

7) To protect transmission line towers, etc. 
by

Related questions

Describe sacrificial anodic protection with neat diagram.

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.

Describe metal spraying process for protection of metal from corrosion .Write its two applications.

Description : Describe metal spraying process for protection of metal from corrosion .Write its two applications.

Last Answer : Process:- i) In this method, coating metal sprayed on the surface of base metal with the help of spraying gun or pistol. ii) The spraying gun consist of a duct for compressed air and is fitted with the oxy- ... 4) Coating of metals like Al, Zn, Ni, Sn, Pb etc. is made by the method of spraying.

Explain cathodic protection. Give one example.

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.  

Classify electrochemical cells. Give examples of each.

Description : Classify electrochemical cells. Give examples of each.

Last Answer : Electrochemical cells are classified as: 1) Primary cells. 2) Secondary cells. Examples of primary cells: Dry Cell (Leclanche’s cell). Daniel Cell. Examples of secondary cells: Lead-acid storage cell. Ni-Cd battery.

Define photo conductive polymer. Give its examples and applications.

Description : Define photo conductive polymer. Give its examples and applications.

Last Answer : Photo conductive polymer: These are the polymers which conduct electricity only in the presence of light. Examples: i) PVK or poly(N-vinyl carbazole ) ii) Poly (vinylpyrene),iii) poly(2- ... resistors are often used include camera light meters, street lights, clock radios and infrared detectors.  

Write two properties and two uses of Bakelite.

Description : Write two properties and two uses of Bakelite.

Last Answer : Properties Uses Hard,Rigid,strong,scratch resistant & brittle material. insulation of electrical wires & cables electrical switches, switch board sockets, plugs for ... Rolling mills, Decorative laminates wall covering & industrial laminates for electrical parts. 

Write two characteristics and two uses of Ni-Cd battery.

Description : Write two characteristics and two uses of Ni-Cd battery.

Last Answer : Characteristics: 1. The e.m.f. of cell is 1.4 V when fully charged. 2. It has low internal resistance & longer life span (5 years). 3. It is expensive in cost. 4. It can be ... lighting and air conditioning because of its long life & low maintenance cost. 3. It is widely used in calculators.

Write two applications and two properties of Rose metal.

Description : Write two applications and two properties of Rose metal.

Last Answer : Properties: 1. It is easily fusible alloy. 2. It’s melting point is 89 0C. Applications: 1. It is used for making fire – alarms, fuses wires. 2. It is used for casting dental works 3. It is used in automatic sprinkler system.

Write two applications of copper.

Description : Write two applications of copper.

Last Answer : 1) For making electrical wires, cables and conducting apparatus. 2) As a coinage metal and in ornaments, jewelry for making them hard. 3) For making water stills, kettles, vacuum pans, steam pipes ... such as hypsometers, colorimeters, etc. 7) For making alloys like brass, bronze, gun metal, etc.

Define adhesive. Write two characteristics of Adhesive.

Description : Define adhesive. Write two characteristics of Adhesive.

Last Answer : Adhesives- Any substance which is capable of holding the materials together by surface attachment is called as an adhesive Characteristics:-  i) Adhesive should form rigid, strong and durable bond. ii ... the adhesion property on storage. v) It should be resistant to heat, chemicals and water.  

Write any two applications of silicon fluid.

Description : Write any two applications of silicon fluid. 

Last Answer : Applications:- 1) As a lubricant: excellent lubrication for plastic and elastomeric surfaces. 2)In polishes and chemical specialities: It is used in automobile and furniture polishes due to its high ... ,non-toxic , non-carbonizing moulds release for rubber, plastics and metal die castings. 

Write any two advantages of Adhesives.

Description : Write any two advantages of Adhesives.

Last Answer : i) Adhesives have an advantage of joining material such as glass & metal, metal metal, metal & plastic, plastics-plastic, ceramic & ceramic. ii) Surfaces are easily & rapidly attached to each ... are leak proof for gases & liquids. So adhesive bonding is used in preparing water tight wood boats

Write two application of metal cladding process.

Description : Write two application of metal cladding process.

Last Answer : Applications : 1) Al clad sheets used in aircraft industry in which a plate of duralumin is sandwiched between two layers of 99.5% pure Al. 2) Cu clad steel wire is obtained by ... cu-tube is used for electrical conductors possessing combining strength of steel with the high conductivity of Cu.

Describe the tinning process. Write its two applications.

Description : Describe the tinning process. Write its two applications.

Last Answer : Tinning: -The process of covering iron or steel sheets with a thin coat of tin to prevent it from rusting is called as tinning.   Process: i) The sheet of steel to be ... Tinned copper sheets are used for cooking utensils and refrigeration equipment. Cu tubes are used in refrigeration. 

Write two applications of Teflon

Description : Write two applications of Teflon

Last Answer : Applications of Teflon: i) Teflon used as capacitor dielectrics & insulating material for all kinds of windings. ii) Heat resistant materials are prepared by combining Teflon with glass cloth. iii ... . vii) Teflon coating is applied on vehicle to protect them from corrosion and scratches. 

Write two points of similarity between sherardizing and galvanising process.

Description : Write two points of similarity between sherardizing and galvanising process.

Last Answer : 1) Sherardizing and galvanizing are the processes of avoiding corrosion of metal. 2) Zinc is used as coating metal on iron base metal.

Write two applications of aluminum

Description : Write two applications of aluminum

Last Answer : 1) For preparing utensils, surgical instruments, heating appliances, parts of aeroplanes, containers for chemical industry etc. 2) For making electric wires and cables for transmission lines. 3) ... storing nitric acid. 13) As refractory for lining of furnace and for making refractory bricks.

Write the action of Nitric acid on Aluminium.

Description : Write the action of Nitric acid on Aluminium.

Last Answer : Aluminium metal does not react with dilute as well as concentrated Nitric acid 

Define specific conductance. Write its unit.

Description : Define specific conductance. Write its unit.

Last Answer : Specific conductance is the conductance offered by 1 cm3 of the substance or 1ml solution.  OR The conductance offered by a solution or a conducting material having unit length & unit area of cross ... conductance. Unit of specific conductance: ohm-1 cm-1 or mhos-cm-1 or S.cm-1

Write the action of water on Aluminium.

Description : Write the action of water on Aluminium.

Last Answer : Pure aluminium is not affected by pure water. However, impure aluminium is readily corroded by water containing salts (seawater). It decomposes boiling water with evolution of hydrogen.

Write the mechanism of corrosion of metal due to action of oxygen.

Description : Write the mechanism of corrosion of metal due to action of oxygen.

Last Answer : Mechanism: Metallic surfaces when exposed to air undergo oxidation and the process of corrosion is represented by the equation.   A thin oxide layer is formed on the metal surface and the nature of this film decides further action depending upon the film so produced.   

Write any four uses of aluminium.

Description : Write any four uses of aluminium.

Last Answer : 1) For preparing utensils, surgical instruments, heating appliances, parts of aeroplanes, containers for chemical industry etc. 2) For making electric wires and cables for transmission lines. 3) ... furnace and for making refractory bricks. 14) For preparation of mirrors for telescope

Write the different types of oxide films formed on the metal surface. Explain the oxide film which is more protective against corrosion.

Description : Write the different types of oxide films formed on the metal surface. Explain the oxide film which is more protective against corrosion.

Last Answer : Types of oxide films 1. Stable porous oxide film 2. Stable non porous oxide film 3. Unstable oxide film 4. Volatile oxide film i) Stable nonporous oxide film ii) Unstable oxide films are protective ... . Example: - Such type of oxide film is formed in the metals like Ag, Au, and Pt.

Write the properties and applications of epoxy resin.

Description : Write the properties and applications of epoxy resin.

Last Answer : Properties: i) They have good chemical resistance. ii) They have low shrinkage during curing. iii) They possess good electrical resistance. iv) These compounds can be used in solid and ... to their electrical resistance they are widely used in making insulators, bushings etc. for high voltage. 

Write four characteristics of good paint.

Description : Write four characteristics of good paint.

Last Answer : i) It should be able to resist the atmospheric conditions. ii) It should have desired consistency. iii) It should have high hiding power. iv) Its film should be washable. v) Its film ... adherent, durable and glossy film.  vii) When paint is applied on a metal, it should resist corrosion.

Define atmospheric corrosion. Write mechanism of atmospheric corrosion with diagram.

Description : Define atmospheric corrosion. Write mechanism of atmospheric corrosion with diagram.

Last Answer : Atmospheric corrosion: This type of corrosion occurs when metal surface comes in immediate contact directly with atmospheric gases like O2, Cl2, Br2, I2, H2S, CO2, SO2, NO2 etc.

Define the term equivalent conductance. Write its unit

Description : Define the term equivalent conductance. Write its unit

Last Answer : Equivalent conductance (λv): It is the conductance of the solution containing 1 gm equivalent of solute / electrolyte when placed between two sufficiently large electrodes 1 cm apart. Unit: ohm-1 cm2 / equivalent OR mhos.cm2 /equivalent 

Write the action of Conc. HNO3 on Aluminium metal.

Description : Write the action of Conc. HNO3 on Aluminium metal.

Last Answer : Aluminum metal does not react with dilute as well as concentrated Nitric acid.

Write four properties and four applications of urea formaldehyde resin.

Description : Write four properties and four applications of urea formaldehyde resin.

Last Answer : Properties: 1) The bond film produced by Urea - Formaldehyde resin is quite rigid & transparent. 2) It is good resistant to moisture, insects & fungi. 3) However action of acids & alkalies ... 3) Used as bonding articles in aircraft. 4) Used as bonding articles in ship building industries etc.

Write the action of water on copper.

Description : Write the action of water on copper.

Last Answer : Water at ordinary temperature has no action on copper. If it is heated to white heat, steam gives Cupric oxide.

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

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

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

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

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

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

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)

Description : 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) ... cathodic base material to be guarded against corrosion (D) All (A), (B) & (C)

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

State the two methods of Hot dipping.

Description : State the two methods of Hot dipping. 

Last Answer : Two methods of hot dipping-1. Galvanizing 2. Tinning

State the two functions of pigment.

Description : State the two functions of pigment.

Last Answer : 1) Provide opacity and colour to paint film. 2) Give strength to the film. 3) Give protection to the paint film by reflecting harmful ultraviolet light. 4) Provide resistance to paint film against abrasion, ... and weather. 5) Give an aesthetical appeal (i.e pleasing to look at) to the paint film.

State two properties and two uses of silicone fluids.

Description : State two properties and two uses of silicone fluids.

Last Answer : Properties :- 1. They can be used in temperature range of -90 0C to 220 0C 2. They have excellent dielectric properties over a wide range of temperature 3. They have ... release material: an odourless, non-toxic, noncarbonizing moulds release for rubber, plastics and metal die castings.

State two applications of lead acid storage cell.

Description : State two applications of lead acid storage cell.

Last Answer : Applications of lead acid storage cell: 1. Lead acid storage cellis commonly used in automobiles. 2. To Supply current for electric vehicles 3. In Gas engine ignition 4. In telephone exchanges ... hospitals 7. In broad casting stations, power stations 8. For distribution work 9. In inverters

Define glass. Give its two characteristics.

Description : Define glass. Give its two characteristics.

Last Answer : Glass is amorphous material which is a mixture of silicates, phosphates, borates and other material with 50-80-% silica . Characteristics: 1) Glass is most widely used as an ... high electric constant. 5) Pyrex glass is most chemically stable and having excellent electrical properties.

Explain fuel cell. State two advantages.

Description : Explain fuel cell. State two advantages.

Last Answer : Fuel cell- Fuel cell is a electrochemical cell which converts the chemical energy of fuels directly into electrical energy by an electrochemical process in which the fuel is oxidized at the ... fossil fuels 15. Fuel cell automotive batteries can render electric vehicles efficient & refillable  

Define paint. Give its two properties

Description : Define paint. Give its two properties

Last Answer : Paint: - Paint is a mechanical dispersion mixture of one or more pigment in a vehicle. Properties of paint: 1) Paint imparts opacity and colour to the surface on which it is applied. 2) It ... and weather. 4) Paint imparts luster, gloss and durability to the surface on which it is applied.

Name two types of adhesives and give their uses.

Description : Name two types of adhesives and give their uses. 

Last Answer : Sr. No. Types of adhesives Uses of adhesives  1 Thermosetting synthetic resins It is used for making water-proof plywoods, laminates, bonding articles in aircraft and ship building ... 7 Animal glues In manufacturing furniture, radio-cabinates and card-boxes etc.

Name any two constituents of paints with two functions of each.

Description : Name any two constituents of paints with two functions of each.

Last Answer : Constituents of paint: 1. Pigments 2. Vehicle or medium (drying oil) 3. Thinners 4. Driers 5. Fillers 6. Plasticizers Functions of various constituents: Pigments: i) Provides opacity and desired ... i) To give elasticity to the paint film. ii) To prevent the cracking of the film.

Name two ores of Aluminum with chemical formulae.

Description : Name two ores of Aluminum with chemical formulae.

Last Answer : Ores of Aluminum:(Any two) i) Bauxite - Al2O3 .2H2O. ii) Corundum- Al2O3, iii) Feldspar - KAlSi3O8, iv) Mica - [KAlSi2O10(OH)2] v) Cryolite - Na3AlF6 vi) Alunite ( Alumstone)- K2SO4 .Al2(SO4)3 .4Al(OH)3

Define charging, discharging, specific resistance and Ohm’s law.

Description : Define charging, discharging, specific resistance and Ohm’s law.

Last Answer : Charging:- It is the operation of the cell in which external source of current reverses the electrochemical cell reaction in order to restore the battery to its original fully charged state. ... across the conductor & inversely proportional to the resistance (R) of a conductor. 

Define extrinsic polymers with example.

Description : Define extrinsic polymers with example.

Last Answer : Extrinsic polymer- The electrical conductivity of polymers can be increased by doping with a charge transfer agent or by making their composites with other conducting materials like ... called as extrinsic polymer  Examples-Trans-polyacetylene, polyparaphenylene, polypyrrole, polyaniline etc. 

Define the term metallurgy. Name the process of extraction of Aluminium.

Description : Define the term metallurgy. Name the process of extraction of Aluminium. 

Last Answer : Metallurgy:-The process of extraction of metal from its ore economically & profitably is called as metallurgy. The process used for extraction of Aluminium metal is Bayer’s process, Electrolytic reduction of alumina, Electrolytic refining. 

What are applications of sherardizing process?

Description : What are applications of sherardizing process?

Last Answer : Applications:- i)Sherardizing is used especially for protecting small odd shaped steel articles like bolts, screws, nuts, threaded parts washers, valves, gauge, tools etc.against atmospheric corrosion. ... has crevices or depression and there is practically no change in the dimensions of articles.

Define immersed corrosion.

Description : Define immersed corrosion.

Last Answer : Definition: The corrosion which is brought about through ionic reactions in the presence of moisture or solution as a conducting medium when two dissimilar metals are in contact with each other is called electro chemical corrosion. 

Define liquid crystal polymers.

Description : Define liquid crystal polymers.

Last Answer : Liquid crystal polymers are a class of aromatic polyester polymers which are capable of forming regions of highly ordered structure (like crystal) even in the liquid phase.