On This Page
This set of Material Science Multiple Choice Questions & Answers (MCQs) focuses on Material Science Set 35
Q1 | in use of speacial alloys, alloying with increases corrosion resistance of brasses and
- cr
- ni
- both a and b
- tin
Q2 | in use of special alloys, for cast irons, addition of increases the corrosion resistance
- cr
- ni
- si
- all of the above
Q3 | in corrosion prevention, the metal to be protected from corrosion is forced to behace like cathode in protection method
- anodic
- cathodic
- both a and b
- none of the above
Q4 | is a type of cathodic protection to prevent corrosion
- sacrificial anodic or galvanic protection
- impressed current cathodic protection
- both a and b
- none of th e above
Q5 | in cathodic protection, the commonly used sacrificial anode is
- al
- mg
- zn
- all of the above
Q6 | is the advantage of sacrificial anodic protection
- no external power is required
- it is easy to install
- installation can be inexpensive if installed at the time of constuction
- all of the above
Q7 | is the limitation of sacrificial anodic protection
- poorly coated structures may require many anodes
- it can be ineffective in high resistivity environment
- installation can be expensive if installed after construction
- all of the above
Q8 | is the application od sacrificial anodic protection
- buried pipelines
- underground cables
- marine structures
- all of the above
Q9 | in , an impressed external current is applied in the opposite direction to the metal to nullify the corrosion current
- impressed current mehtod ofcathodic
- sacrificial anodic protection
- galvanic anodic protection
- anodic protection
Q10 | is the advantage of impressed current method of cathodic protection
- it can be designed for a wide range of voltage and current
- it can be applied in high resistivity environment
- effective in protecting uncaoted and poorly coated structures
- all of the above
Q11 | is the limitation of impressed current method of cathodic protection
- it can cause cathodic interference problems
- require peroidic maintenance
- require external power, resulting in monthly power costs
- all of the above
Q12 | is the application of impressed current method of cathodic protection
- open water box coolers
- condensers
- laid up ships
- all of the above
Q13 | 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
- activity
- passivity
- both a and b
- none of the above
Q14 | passivity phenomenon of anodic protection is quite common with metal like
- al
- ni
- tin
- all of the above
Q15 | 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
- sacrificial anodic or galvanic protection
- galvanic protection
- anodic protection
- impressed current of cathodic protection
Q16 | is ha davantage of anodic protection to prevent corrosion
- anodic protection has greaterthrowing
- method can be applied to severlycorrosiong
- it requires low current density,hence its
- all of the above
Q17 | is the limitation of anodic protection to prevent corrosion
- applicable only to those metals and alloys which exibit passivity
- some corrosion take place at a slow rates
- both a and b
- none of the above
Q18 | the method of anodic protetion can be applied to carrying corrosives chemical to prevent corrosion
- stainless steel containers
- chemical reactors
- tanks and pipes
- all of the above
Q19 | the protective coatings applied to prevent corrosion should have the property of
- a good corrosionresi stance
- perfect adherence to underlying metal
- completely cover the surface
- all of the above
Q20 | the most common non metallic coating used to prevent corrosion of metals is
- paints
- enamels
- porcelain
- all of the above
Q21 | in metallic coating of metals afford galvanic protection to the steel
- zinc
- cadmium
- both a and b
- tin
Q22 | is the method to apply metallic coating to prevent corrosion
- hot dipping
- metal spraying
- electrplating
- all of the above
Q23 | coatings are very useful for protecting undergraound tanks and pipes from corrosion
- bituminous
- paints
- zinc
- cadmium
Q24 | is the most widely used material
- pitch
- paints
- bitumen
- none of the
Q25 | oxidizing substances like is used as anodic inhibitors for the protection of iron and steel from corrosion
- chromates
- nitrates
- phosphates
- all of the above