Engineering Materials Mcqs - Set 5

1)   The metallic structure of mild steel is_________________?

a. body centred cubic
b. face centred cubic
c. hexagonal close packed
d. cubic structure
e. orthorhombic crystal
Answer  Explanation 

ANSWER: body centred cubic

Explanation:
No explanation is available for this question!


2)   The crystal structure of gamma iron is_________________?

a. body centred cubic
b. face centred cubic
c. hexagonal close packed
d. cubic structure
e. orthorhombic crystal
Answer  Explanation 

ANSWER: face centred cubic

Explanation:
No explanation is available for this question!


3)   Paramagnetic alpha iron changes to gamma iron at_______________?

a. 770°C
b. 910°C
c. 1440°C
d. 1539°C
e. none of the above
Answer  Explanation 

ANSWER: 910°C

Explanation:
No explanation is available for this question!


4)   The molecules in a solid move______________?

a. in a random manner
b. in a haphazard way
c. in circular motion
d. back and forth like tiny pendulums
e. do not move
Answer  Explanation 

ANSWER: back and forth like tiny pendulums

Explanation:
No explanation is available for this question!


5)   Cast iron is characterised by minimum of following %age of carbon_________________?

a. 0.2%
b. 0.8%
c. 1.3%
d. 2%
e. 6.3%.
Answer  Explanation 

ANSWER: 2%

Explanation:
No explanation is available for this question!


6)   Pure iron is the structure of_______________?

a. ferrite
b. pearlite
c. anstenite
d. ferrite and cementite
e. ferrite and pearlite
Answer  Explanation 

ANSWER: ferrite

Explanation:
No explanation is available for this question!


7)   Gamma iron exits at following temperature___________________?

a. room temperature
b. near melting point
c. between 1400°C and 1539°C
d. between 910°C and 1400°C
e. none of the above
Answer  Explanation 

ANSWER: between 910°C and 1400°C

Explanation:
No explanation is available for this question!


8)   Which of the following represents the allotropic forms of iron__________________?

a. alpha iron, beta iron and gamma iron
b. alpha iron and beta iron
c. body centred cubic a-iron and face centred cubic a-iron
d. alpha iron, gamma from and delta iron
e. none of the above
Answer  Explanation 

ANSWER: alpha iron, gamma from and delta iron

Explanation:
No explanation is available for this question!


9)   Super conduction by metals is observed in the temperature range of_________________?

a. below 10°K
b. above 100°K
c. around 0°C
d. around 100°C
e. above 1000°C
Answer  Explanation 

ANSWER: below 10°K

Explanation:
No explanation is available for this question!


10)   Delta iron occurs at temperature of_______________?

a. room temperature
b. above melting point
c. between 1400°C and 1539°C
d. between 910°C and 1400°C
e. none of the above
Answer  Explanation 

ANSWER: between 1400°C and 1539°C

Explanation:
No explanation is available for this question!


11)   Recrystallization temperature is one________________?

a. at which crystals first start forming from molten metal when it is cooled
b. at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated
c. at which change of allotropic form takes place
d. at which crystals grow bigger in size
e. at which crystals are destroyed on heating
Answer  Explanation 

ANSWER: at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated

Explanation:
No explanation is available for this question!


12)   The elastic stress strain behaviour of rubber is_____________________?

a. linear
b. non-linear
c. plastic
d. no fixed relationship
e. unpredictable behaviour
Answer  Explanation 

ANSWER: non-linear

Explanation:
No explanation is available for this question!


13)   The number of electrons in 1 cm3 of metal would be of the order of_______________?

a. 1010
b. TO16
c. 1022
d. 1040
e. 1052
Answer  Explanation 

ANSWER: 1022

Explanation:
No explanation is available for this question!


14)   Slow plastic defomiation of metals under a constant stress is known as________________?

a. creep
b. fatigue
c. endurance
d. plastic deformation
e. non-plastic deformation
Answer  Explanation 

ANSWER: creep

Explanation:
No explanation is available for this question!


15)   In compression, a prism of brittle material will break________________?

a. by forming a bulge (l>) by shearing along oblique plane
b. in direction perpendicular to application of load
c. by crushing into thousands of pieces
d. none of the above
Answer  Explanation 

ANSWER: by forming a bulge (l>) by shearing along oblique plane

Explanation:
No explanation is available for this question!


16)   Ductility of a material can be defined as__________________?

a. ability to undergo large permanent deformations in compression
b. ability to recover its original form
c. ability to undergo large permanent deformations in tension
d. all of the above
e. none of the above
Answer  Explanation 

ANSWER: ability to undergo large permanent deformations in tension

Explanation:
No explanation is available for this question!


17)   The ultimate tensile strength of low carbon steel by working at a high strain rate will_________________?

a. decrease
b. increase
c. remain constant
d. first increase and then decrease
e. first decrease and then increase
Answer  Explanation 

ANSWER: increase

Explanation:
No explanation is available for this question!


18)   Sulphur in steel________________?

a. acts as deoxidiser
b. reduces the grain size
c. decreases tensile strength and hardness
d. lowers the toughness and transverse ductility
e. increases hardness
Answer  Explanation 

ANSWER: lowers the toughness and transverse ductility

Explanation:
No explanation is available for this question!


19)   Tungsten in high speed steel provides________________?

a. hot hardness
b. toughness
c. wear resistance
d. sharp cutting edge
e. cold hardness
Answer  Explanation 

ANSWER: hot hardness

Explanation:
No explanation is available for this question!


20)   Connecting rod is usually made of_________________?

a. aluminium
b. low carbon steel
c. medium carbon steel
d. high carbon steel
e. cast iron
Answer  Explanation 

ANSWER: medium carbon steel

Explanation:
No explanation is available for this question!