Damage to metal surface by mechanical action is called (A) Pitting (B) Corrosion (C) Erosion (D) None of these

Damage to metal surface by mechanical action is called
(A) Pitting
(B) Corrosion
(C) Erosion
(D) None of these
by

1 Answer

Answer :

Option C
by

Related questions

_____ 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

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

Identify the false statement (A) Martensitic steels are less susceptible to pitting corrosion than austenitic steels (B) Pitting corrosion is usually very localised (C) Hydrogen embrittlement is facilitated by tensile stress (D) Stress corrosion cracking is facilitated by tensile stress

Description : Identify the false statement (A) Martensitic steels are less susceptible to pitting corrosion than austenitic steels (B) Pitting corrosion is usually very localised (C) Hydrogen embrittlement is facilitated by tensile stress (D) Stress corrosion cracking is facilitated by tensile stress

Last Answer : (A) Martensitic steels are less susceptible to pitting corrosion than austenitic steels

Widening of a river valley takes place due to – (1) Corrosion (2) Lateral erosion (3) Corrasion (4) Hydraulic action

Description : Widening of a river valley takes place due to – (1) Corrosion (2) Lateral erosion (3) Corrasion (4) Hydraulic action

Last Answer : (2) Lateral erosion Explanation: Lateral or sideways erosion widens the river valley; while, Vertical or downward erosion deepens the river valley. Due to continued lateral erosion, the river ... slopes are also eroded by weathering and mass wasting and by the development of tributary valleys.

Widening of a river valley takes place due to (1) Corrosion (2) Lateral erosion (3) Corrasion (4) Hydraulic action

Description : Widening of a river valley takes place due to (1) Corrosion (2) Lateral erosion (3) Corrasion (4) Hydraulic action

Last Answer : Lateral erosion

The deterioration of a metal by an electrochemical process is commonly termed as – (1) Erosion (2) Corrosion (3) Passivation (4) Abrasion

Description : The deterioration of a metal by an electrochemical process is commonly termed as – (1) Erosion (2) Corrosion (3) Passivation (4) Abrasion

Last Answer : (2) Corrosion Explanation: Corrosion can be defined as the deterioration of materials by chemical processes.

The deterioration of a metal by an electrochemical process is commonly termed as (1) Erosion (2) Corrosion (3) Passivation (4) Abrasion

Description : The deterioration of a metal by an electrochemical process is commonly termed as (1) Erosion (2) Corrosion (3) Passivation (4) Abrasion

Last Answer : Corrosion

The damage/deterioration of metals by the __________ action of fluids is called 'erosion'. (A) Abrasive (B) Corrosive (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The damage/deterioration of metals by the __________ action of fluids is called 'erosion'. (A) Abrasive (B) Corrosive (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (A) Abrasive

In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

Description : In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

Last Answer : (C) Positive pressure exists in the furnace

Corrosion is (A) A physical phenomenon (B) A chemical phenomenon (C) Same as erosion (D) An uncontrollable phenomenon

Description : Corrosion is (A) A physical phenomenon (B) A chemical phenomenon (C) Same as erosion (D) An uncontrollable phenomenon

Last Answer : Option B

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.   

The sideways erosion which widens the river valley called? (1) Lateral Corrosion (2) Vertical Corrosion (3) Side Corrosion (4) Mean Corrosion

Description : The sideways erosion which widens the river valley called? (1) Lateral Corrosion (2) Vertical Corrosion (3) Side Corrosion (4) Mean Corrosion

Last Answer : (1) Lateral Corrosion Explanation: Sideways form of erosion is called lateral erosion. In lateral erosion, the river erodes away at its banks and widens the river channel. Together, vertical and lateral erosion create the distinctive V-shaped valley that is found in rivers in their upper course.

Out of the following processes of paper pulp manufacture, the maximum corrosion problem in digestion & handling equipments is encountered in the __________ process. (A) Mechanical (B) Sulphate/Kraft (C) Sulphite (D) Neutral sulphite semi-chemical

Description : Out of the following processes of paper pulp manufacture, the maximum corrosion problem in digestion & handling equipments is encountered in the __________ process. (A) Mechanical (B) Sulphate/Kraft (C) Sulphite (D) Neutral sulphite semi-chemical

Last Answer : (D) Neutral sulphite semi-chemical

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

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

Close inspection of a failed metal part reveals artifacts on the fracture surface commonly referred to as "striations" or "beach marks". This indicates the component failed as a result of: w) Sudden overloading x) Cyclical loading y) Stress corrosion cracking z) None of the above

Description : Close inspection of a failed metal part reveals artifacts on the fracture surface commonly referred to as "striations" or "beach marks". This indicates the component failed as a result of: w) Sudden overloading x) Cyclical loading y) Stress corrosion cracking z) None of the above

Last Answer : ANSWER: X -- CYCLICAL LOADING

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.

The removal of paint from electrical equipment, such as generators, should be cautiously undertaken because ____________. A. the mechanical shock of paint removal lessens the dielectric strength of the insulation B. the paint dust is composed of abrasive and semi-conducting materials which impair insulation C. paint dust buildup has a tendency to cause corrosion D. phase windings frequently become isolated from each other due to dust interference at the terminals

Description : The removal of paint from electrical equipment, such as generators, should be cautiously undertaken because ____________. A. the mechanical shock of paint removal lessens the dielectric strength ... phase windings frequently become isolated from each other due to dust interference at the terminals

Last Answer : Answer: B

What material is applied to electronic assemblies to prevent damage from corrosion, moisture, and stress?

Description : What material is applied to electronic assemblies to prevent damage from corrosion, moisture, and stress?

Last Answer : Conformal coating

The main purpose of an electric space heater installed in a large AC generator is to _____________. A. keep the lube oil warm for quick starting B. prevent moisture from condensing in the windings when the machine is shutdown C. prevent the windings from becoming brittle D. prevent acidic pitting of the slip rings

Description : The main purpose of an electric space heater installed in a large AC generator is to _____________. A. keep the lube oil warm for quick starting B. prevent moisture from condensing in the ... is shutdown C. prevent the windings from becoming brittle D. prevent acidic pitting of the slip rings

Last Answer : Answer: B

In an A.C. generator, pitting of collector rings will cause __________. I. sparking II. Chattering A. I only B. II only C. both I and II D. neither I or II

Description : In an A.C. generator, pitting of collector rings will cause __________. I. sparking II. Chattering A. I only B. II only C. both I and II D. neither I or II

Last Answer : Answer: D

The main purpose of an electric space heater installed in a large AC generator is to _____________. A. prevent the windings from becoming brittle B. prevent moisture from condensing in the windings during shutdown C. prevent acidic pitting of the slip rings D. keep the lube oil warm for quick starting

Description : The main purpose of an electric space heater installed in a large AC generator is to _____________. A. prevent the windings from becoming brittle B. prevent moisture from condensing in the windings during ... C. prevent acidic pitting of the slip rings D. keep the lube oil warm for quick starting

Last Answer : Answer: B

The pitting of controller contacts can be caused by _____________. A. excessive spring pressure B. insufficient contact pressure C. continuous motor overload D. all of the above

Description : The pitting of controller contacts can be caused by _____________. A. excessive spring pressure B. insufficient contact pressure C. continuous motor overload D. all of the above

Last Answer : Answer: B

What is pitting ? How it is caused ?

Description : What is pitting ? How it is caused ?

Last Answer : Non uniform corrosion over the entire metal surface, but occuring only in small pits is called pitting. It is caused by lack of uniformity in metal.

Extreme Pressure (EP) additives cause ______ wear in the bearing parts. (a) abrasive (b) corrosive (c) pitting (d) fatigue

Description : Extreme Pressure (EP) additives cause ______ wear in the bearing parts. (a) abrasive (b) corrosive (c) pitting (d) fatigue

Last Answer : (b) corrosive

Extreme pressure causes ______ wear in the bearing parts. a) Abrasive b) Corrosive c) Pitting d) All of the mentioned

Description : Extreme pressure causes ______ wear in the bearing parts. a) Abrasive b) Corrosive c) Pitting d) All of the mentioned

Last Answer : b) Corrosive

Stress concentration is caused due to A. Variation in properties of material from point to point in a member B. Pitting at points or areas at which loads on a member are applied C. Abrupt change of section D. All of the above

Description : Stress concentration is caused due to A. Variation in properties of material from point to point in a member B. Pitting at points or areas at which loads on a member are applied C. Abrupt change of section D. All of the above

Last Answer : D. All of the above

A patient presents with long time history of knee pain suggestive of osteoarthritis. Now he complains of unilateral lower limb swelling and on examination there is +ve pedal & tibial pitting edema. What is the next appropriate investigation? a. CXR b. ECG c. Echocardiography d. Duplex ultrasound of lower limb

Description : A patient presents with long time history of knee pain suggestive of osteoarthritis. Now he complains of unilateral lower limb swelling and on examination there is +ve pedal & tibial pitting edema ... appropriate investigation? a. CXR b. ECG c. Echocardiography d. Duplex ultrasound of lower limb

Last Answer : d. Duplex ultrasound of lower limb

The most popular mechanical measure to control soil erosion and conserve is

Description : The most popular mechanical measure to control soil erosion and conserve is

Last Answer : Ans.Contour Bunding

Which of the following processes is responsible for producing the sand dunes in western Rajasthan? (1) Wind erosion (2) Erosion by water (3) Wind deposition (4) Mechanical weathering

Description : Which of the following processes is responsible for producing the sand dunes in western Rajasthan? (1) Wind erosion (2) Erosion by water (3) Wind deposition (4) Mechanical weathering

Last Answer : (3) Wind deposition Explanation: In physical geography, a dune is a hill of sand built either by wind or water flow. Dunes occur in different forms and sizes, formed by interaction with the flow ... the sand grains: and (3) a topography whereby the sand particles lose their momentum and settle out.

Which of the following processes is responsible for producing the sand dunes in western Rajasthan ? (1) Wind erosion (2) Erosion by water (3) Wind deposition (4) Mechanical weathering

Description : Which of the following processes is responsible for producing the sand dunes in western Rajasthan ? (1) Wind erosion (2) Erosion by water (3) Wind deposition (4) Mechanical weathering

Last Answer : Wind deposition

The principal cause of soil damage in Punjab and Haryana is (a) Deforestation (b) Soil erosion (c) Excessive cultivation (d) Salinity and water logging

Description : The principal cause of soil damage in Punjab and Haryana is (a) Deforestation (b) Soil erosion (c) Excessive cultivation (d) Salinity and water logging

Last Answer : Ans: (d)

Which of the following indicates the types of soil erosion in decreasing order of damage caused In India (a) Ravine erosion .and gullies, alkalinity and salinity weeds and water-logging (b) Alkalinity and water-logging, ravine erosion and weeds (c) Water-logging, weeds, salinity and ravine erosion (d) All are equally damaging

Description : Which of the following indicates the types of soil erosion in decreasing order of damage caused In India (a) Ravine erosion .and gullies, alkalinity and salinity weeds and water-logging (b) Alkalinity ... and weeds (c) Water-logging, weeds, salinity and ravine erosion (d) All are equally damaging

Last Answer : Ans: (a)

Channelization of streams is designed to reduce flooding by ___________. a) Speeding the passage of floodwaters b) Reducing bank erosion c) Slowing down river velocity so as to reduce damage d) Increase the meandering of streams

Description : Channelization of streams is designed to reduce flooding by ___________. a) Speeding the passage of floodwaters b) Reducing bank erosion c) Slowing down river velocity so as to reduce damage d) Increase the meandering of streams

Last Answer : a) Speeding the passage of floodwaters

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

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

A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity

Description : A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity

Last Answer : (A) More corrosion resistant

Electrochemical corrosion can occur, only if __________ is present in contact with metal. (A) Air (B) Oxygen (C) Liquid medium (D) Gaseous medium

Description : Electrochemical corrosion can occur, only if __________ is present in contact with metal. (A) Air (B) Oxygen (C) Liquid medium (D) Gaseous medium

Last Answer : (C) Liquid medium

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 chromate coating (C) The base metal to be electroplated is normally made the cathode of the electrolytic cell and coating metal is made the anode (D) Calorising is the process of coating steel with chromium

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

With increase in impurities in metals, their corrosion resistances (A) Increase (B) Decrease (C) Remain same (D) May increase or decrease; depending on the type of metal

Description : With increase in impurities in metals, their corrosion resistances (A) Increase (B) Decrease (C) Remain same (D) May increase or decrease; depending on the type of metal

Last Answer : (B) Decrease

In connection with corrosion of metals, passivation is the process that (A) Intensifies deterioration (B) Changes the composition of the metal (C) Inhibits further deterioration (D) None of these

Description : In connection with corrosion of metals, passivation is the process that (A) Intensifies deterioration (B) Changes the composition of the metal (C) Inhibits further deterioration (D) None of these

Last Answer : (C) Inhibits further deterioration

. Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation

Description : . Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation

Last Answer : (C) Give elasticity & prevent cracking of the film

. Carboxymethyl cellulose (CMC) is added in detergents to (A) Prevent redeposition of soil on cleaned surface (B) Act as optical brightening agent (C) Inhibit corrosion in washing machines made of aluminium (D) None of these

Description : . Carboxymethyl cellulose (CMC) is added in detergents to (A) Prevent redeposition of soil on cleaned surface (B) Act as optical brightening agent (C) Inhibit corrosion in washing machines made of aluminium (D) None of these

Last Answer : (A) Prevent redeposition of soil on cleaned surface

__________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C. (A) Veneering (B) Galvanising (C) Electroplating (D) Calorising

Description : __________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C. (A) Veneering (B) Galvanising (C) Electroplating (D) Calorising

Last Answer : (D) Calorising

The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

Description : The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

Last Answer : [ D ] carbonation

The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

Description : The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

Last Answer : [ D ] carbonation

The air gap provided in induction motors should be checked periodically with a feeler gage to detect an unequal air gap and _____________. A. decreased motor magnetizing current B. hysteresis loses C. increased power factor D. mechanical damage to the rotor

Description : The air gap provided in induction motors should be checked periodically with a feeler gage to detect an unequal air gap and _____________. A. decreased motor magnetizing current B. hysteresis loses C. increased power factor D. mechanical damage to the rotor

Last Answer : Answer: D

When soldering a printed circuit board component, you should be careful to prevent damage by _________. A. quickly heating the joints, using a high wattage iron B. using the soldering iron tip sparingly C. using only acid cord solder D. applying mechanical pressure to the joints being soldered

Description : When soldering a printed circuit board component, you should be careful to prevent damage by _________. A. quickly heating the joints, using a high wattage iron B. using the soldering iron tip sparingly C. using only acid cord solder D. applying mechanical pressure to the joints being soldered

Last Answer : Answer: B

When a solid-state component of an electronic circuit is mounted to a metallic mass, the general purpose of that mass is to ____________. A. prevent vibration damage to delicate components B. prevent mechanical damage to solid-state components C. dissipate stray magnetic currents D. act as a heat sink

Description : When a solid-state component of an electronic circuit is mounted to a metallic mass, the general purpose of that mass is to ____________. A. prevent vibration damage to delicate components B. prevent ... damage to solid-state components C. dissipate stray magnetic currents D. act as a heat sink

Last Answer : Answer: D

Of the following, which mechanisms are important i the death of erythrocytes (pron: eh-rith-reh-sites) in human blood? Is it a) phagocytosis (pron: fag-eh-seh-toe-sis) b) hemolysis c) mechanical damage d) all of the above

Description : Of the following, which mechanisms are important i the death of erythrocytes (pron: eh-rith-reh-sites) in human blood? Is it a) phagocytosis (pron: fag-eh-seh-toe-sis) b) hemolysis c) mechanical damage d) all of the above

Last Answer : ANSWER: D -- all of the above

Why acid causes corrosion of metal ?

Description : Why acid causes corrosion of metal ?

Last Answer : We heard about acid. I know it dissolves other solids. Many times some professional thieves melt the lock with acid without breaking the lock for theft. So how did the acid get such horrible properties ... in a piece of metal decreases. This is why exposure to acid actually causes metal to decay.