MCQOPTIONS
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MCQOPTIONS
This section includes 1232 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 351. |
phenomenon of crevice corrosion is based on |
| A. | electrochemi cal corrosion |
| B. | electromenta l corrosion |
| C. | electromech anical corrosion |
| D. | none of the above |
| Answer» B. electromenta l corrosion | |
| 352. |
crevice corrosion rate become faster due to |
| A. | gases in the liquid or electrolyte |
| B. | high flow of liquid or electrolyte |
| C. | trapped stagnant liquids, which is highly concentrated |
| D. | none of the above |
| Answer» D. none of the above | |
| 353. |
pitting corrosion is a bimetal corrosion, the statement is |
| A. | true |
| B. | false |
| C. | not applicable to it |
| D. | none of the above |
| Answer» C. not applicable to it | |
| 354. |
galvanic corrosion is a highly localized corrosion, the statement is |
| A. | false |
| B. | true |
| C. | not applicable to it |
| D. | none of the above |
| Answer» B. true | |
| 355. |
pitting corrosion is also known as |
| A. | low temperature corrosion |
| B. | high temperature corrosion |
| C. | bimetal corrosion |
| D. | none of the above |
| Answer» E. | |
| 356. |
in galvanic corrosion, as the area of anode metal decreases with respect to cathode area of metal, the corrosion rate |
| A. | increases |
| B. | decreases |
| C. | remain constant |
| D. | none of the above |
| Answer» B. decreases | |
| 357. |
which of the following methods are used ot reduce galvanic corrosion ? |
| A. | select two metals that are close together in the galvanic corrosion |
| B. | avoid relatively small area of less noble metal and large area of more noble metal |
| C. | insulate the metal from each other |
| D. | all of the above |
| Answer» E. | |
| 358. |
which of the following is essential requirement for the galvanic corrosion to occur ? |
| A. | an electrolyte in contact with two metals |
| B. | electrical contact between two metals |
| C. | a difference of potential between two metals |
| D. | all of the above |
| Answer» E. | |
| 359. |
the best and economic way of preventing general corrosion is |
| A. | coating the metal |
| B. | cathodic protection |
| C. | using proper inhibitors |
| D. | all of the above |
| Answer» E. | |
| 360. |
galvanic corrosion is also known as |
| A. | bimetallic corrosion |
| B. | dry corrosion |
| C. | high temperature corrosion |
| D. | low temperature corrosion |
| Answer» B. dry corrosion | |
| 361. |
the best example of general corrosion is |
| A. | corrosion of manhole cover |
| B. | corrosion of springs |
| C. | corrosion of fasteners |
| D. | none of the above |
| Answer» B. corrosion of springs | |
| 362. |
general corrosion is also known as |
| A. | uniform corrosion |
| B. | localised corrosion |
| C. | harmless corrosion |
| D. | all of the above |
| Answer» B. localised corrosion | |
| 363. |
wet corrosion is based on which phenomenon |
| A. | electro- mechaniacl |
| B. | electro- chemical |
| C. | electro- biologica l |
| D. | none of the above |
| Answer» C. electro- biologica l | |
| 364. |
what is nature of oxide film formed on the aluminium and copper metal due to reaction with atmosphere |
| A. | porous |
| B. | non-porous |
| C. | silky |
| D. | none of the above |
| Answer» C. silky | |
| 365. |
what is the nature of oxide film, formed on the ferrous metal due to reaction with atmosphere? |
| A. | porous |
| B. | non-porous |
| C. | silky |
| D. | all of the above |
| Answer» E. | |
| 366. |
dry corrosion is taking place due to |
| A. | when carbon dioxide in the air reacts with metal |
| B. | when nitrogen in the air reacts with metal |
| C. | when sulphur in the air reacts with the metal |
| D. | when oxygen in the air reacts with metal |
| Answer» E. | |
| 367. |
which of the factor given below, influencing corrosion of steel? |
| A. | temperature |
| B. | oxygen in the atmosphere |
| C. | moisture |
| D. | all of the above |
| Answer» E. | |
| 368. |
in electrochemical corrosion at anode, which type of chemical reaction is taking |
| A. | eutectic reaction |
| B. | peritectic reaction |
| C. | eutectoid reaction |
| D. | none of the above |
| Answer» E. | |
| 369. |
in electrochemical corrosion, at cathode which type of chemical reaction taking place |
| A. | metallic reaction |
| B. | reduction reaction |
| C. | oxidation reaction |
| D. | none of the above |
| Answer» C. oxidation reaction | |
| 370. |
in electrochemical corrosion, at cathode which type of chemical reaction is taking place |
| A. | peretectic reaction |
| B. | eutectic reaction |
| C. | eutectoid reaction |
| D. | none of the above |
| Answer» E. | |
| 371. |
in electrochemical corrosion, at anode which type of chemical reaction taking place |
| A. | oxidation reaction |
| B. | reduction reaction |
| C. | metallic reation |
| D. | none of the above |
| Answer» B. reduction reaction | |
| 372. |
on of the metal stated below is highly corrodent |
| A. | cast iron |
| B. | high carbon steel |
| C. | mild steel |
| D. | all of the above |
| Answer» E. | |
| 373. |
all the metals stated below are very sensitive to corrosion |
| A. | silver |
| B. | gold |
| C. | copper |
| D. | none of the above |
| Answer» E. | |
| 374. |
on of following metal do not corrode |
| A. | steel |
| B. | cast iron |
| C. | aluminium |
| D. | none of the above |
| Answer» D. none of the above | |
| 375. |
for corrosion to takes place, there is need of |
| A. | only anode |
| B. | only anode |
| C. | only anode, cathode and |
| D. | none of the |
| Answer» D. none of the | |
| 376. |
the natural tendency of metal to revert back its original form, due to corrosion is termed as |
| A. | stress corrosion |
| B. | corrosion fatigue |
| C. | general corrosion |
| D. | corrosion cycle |
| Answer» E. | |
| 377. |
corrosion give large impact on SHE, that is |
| A. | shell, harvest, equation |
| B. | stamp, heat and equilateral |
| C. | safety, health and environment |
| D. | none of the above |
| Answer» D. none of the above | |
| 378. |
corrosion is defined as - |
| A. | the deterioration of environment |
| B. | the deterioration of metal |
| C. | the deterioration of both metal and environment |
| D. | none of the above |
| Answer» C. the deterioration of both metal and environment | |
| 379. |
                               inhibitors prevent evolution of hydrogen (in case of acidic solution) and oxygen absorption (in case of neutral solution) to prevent corrosion |
| A. | cathodic |
| B. | anodic |
| C. | both a and b |
| D. | none of the above |
| Answer» B. anodic | |
| 380. |
                         are used as cathodic inhibitors to prevent corrosion of metals |
| A. | chromates |
| B. | nitrates |
| C. | antimony and arsenic oxides |
| D. | phosphates |
| Answer» D. phosphates | |
| 381. |
oxidizing substances like is used as anodic inhibitors for the protection of iron and steel from corrosion |
| A. | chromates |
| B. | nitrates |
| C. | phosphates |
| D. | all of the above |
| Answer» E. | |
| 382. |
                      is the most widely used material |
| A. | pitch |
| B. | paints |
| C. | bitumen |
| D. | none of the |
| Answer» C. bitumen | |
| 383. |
                       coatings are very useful for protecting undergraound tanks and pipes from corrosion |
| A. | bituminous |
| B. | paints |
| C. | zinc |
| D. | cadmium |
| Answer» B. paints | |
| 384. |
                 is the method to apply metallic coating to prevent corrosion |
| A. | hot dipping |
| B. | metal spraying |
| C. | electrplating |
| D. | all of the above |
| Answer» E. | |
| 385. |
in metallic coating of metals afford galvanic protection to the steel |
| A. | zinc |
| B. | cadmium |
| C. | both a and b |
| D. | tin |
| Answer» D. tin | |
| 386. |
the most common non metallic coating used to prevent corrosion of metals is |
| A. | paints |
| B. | enamels |
| C. | porcelain |
| D. | all of the above |
| Answer» E. | |
| 387. |
the protective coatings applied to prevent corrosion should have the property of |
| A. | a good corrosionresi stance |
| B. | perfect adherence to underlying metal |
| C. | completely cover the surface |
| D. | all of the above |
| Answer» E. | |
| 388. |
the method of anodic protetion can be applied to carrying corrosives chemical to prevent corrosion |
| A. | stainless steel containers |
| B. | chemical reactors |
| C. | tanks and pipes |
| D. | all of the above |
| Answer» E. | |
| 389. |
                         is the limitation of anodic protection to prevent corrosion |
| A. | applicable only to those metals and alloys which exibit passivity |
| B. | some corrosion take place at a slow rates |
| C. | both a and b |
| D. | none of the above |
| Answer» D. none of the above | |
| 390. |
                       is ha davantage of anodic protection to prevent corrosion |
| A. | anodic protection has greater throwing |
| B. | method can be applied to severly corrosiong |
| C. | it requires low current density, hence its |
| D. | all of the above |
| Answer» E. | |
| 391. |
in protection method, the part of metal to be protected from corrosion is made anodic by passing an impressed direct current in the same direction as that of corrosion current |
| A. | sacrificial anodic or galvanic protection |
| B. | galvanic protection |
| C. | anodic protection |
| D. | impressed current of cathodic protection |
| Answer» D. impressed current of cathodic protection | |
| 392. |
passivity phenomenon of anodic protection is quite common with metal like |
| A. | al |
| B. | ni |
| C. | tin |
| D. | all of the above |
| Answer» E. | |
| 393. |
                       is the phenomenon in which a metal or an alloy exibits higher corrosion resistabce than expected from its position in the electrochemical series by forming protective, thin, nonporous oxide film on the surface |
| A. | activity |
| B. | passivity |
| C. | both a and b |
| D. | none of the above |
| Answer» C. both a and b | |
| 394. |
                         is the application of impressed current method of cathodic protection |
| A. | open water box coolers |
| B. | condensers |
| C. | laid up ships |
| D. | all of the above |
| Answer» E. | |
| 395. |
                 is the limitation of impressed current method of cathodic protection |
| A. | it can cause cathodic interference problems |
| B. | require peroidic maintenance |
| C. | require external power, resulting in monthly power costs |
| D. | all of the above |
| Answer» E. | |
| 396. |
                     is the advantage of impressed current method of cathodic protection |
| A. | it can be designed for a wide range of voltage and current |
| B. | it can be applied in high resistivity environment |
| C. | effective in protecting uncaoted and poorly coated structures |
| D. | all of the above |
| Answer» E. | |
| 397. |
in , an impressed external current is applied in the opposite direction to the metal to nullify the corrosion current |
| A. | impressed current mehtod of cathodic |
| B. | sacrificial anodic protection |
| C. | galvanic anodic protection |
| D. | anodic protection |
| Answer» B. sacrificial anodic protection | |
| 398. |
                         is the application od sacrificial anodic protection |
| A. | buried pipelines |
| B. | underground cables |
| C. | marine structures |
| D. | all of the above |
| Answer» E. | |
| 399. |
                       is the limitation of sacrificial anodic protection |
| A. | poorly coated structures may require many anodes |
| B. | it can be ineffective in high resistivity environment |
| C. | installation can be expensive if installed after construction |
| D. | all of the above |
| Answer» E. | |
| 400. |
                     is the advantage of sacrificial anodic protection |
| A. | no external power is required |
| B. | it is easy to install |
| C. | installation can be inexpensive if installed at the time of constuction |
| D. | all of the above |
| Answer» E. | |