Engineering Questions with Answers - Multiple Choice Questions
Materials Science MCQ’s – Steels
1 - Question
Which of the following is an alloy of iron and carbon?
a) Steel
b) Brass
c) Bronze
d) Solder
View Answer
Explanation: Steel is an alloy of iron and carbon while solder, bronze and brass are alloys of different metal other than iron.
2 - Question
Which of following crystalline form can iron not take?
a) BCC
b) FCC
c) HCP
d) It can take all crystalline forms
View Answer
Explanation: The correct answer is HCP or hexagonal close packing. Iron can take the crystalline structure of BCC and FCC according to the temperature.
3 - Question
Which of the following can be the carbon weight percentage in steel?
a) 2%
b) 5%
c) 3%
d) 4%
View Answer
Explanation: In a typical steel, the carbon may contribute the maximum of 2.14% of the weight of the alloy. Therefore only 2% lies within the range and hence is the correct answer.
4 - Question
Which of the following cannot be used as an alloying element in steel?
a) Lead
b) Chromium
c) Nickel
d) Tungsten
View Answer
Explanation: Lead cannot be used as an alloying element in steel. While chromium, nickel and tungsten are used as an alloying element in steel according to which the carbon percentage in the steel is found out.
5 - Question
Traces of which of the following element is considered undesirable in steel?
a) Chromium
b) Copper
c) Boron
d) Titanium
View Answer
Explanation: Traces of copper, oxygen and nitrogen are undesirable in a steel alloy whereas chromium, boron and titanium are common alloying elements of steel alloy.
6 - Question
Which of the following element is added to steel to form stainless steel?
a) Chromium
b) Copper
c) Boron
d) Titanium
View Answer
Explanation: Chromium is added to steel to inhibit corrosion and in a quantity of at least 11%. An oxide protection is formed on the surface of the steel, the alloy thus formed is called stainless steel.
7 - Question
At room temperature which is the most stable form of iron?
a) Pearlite
b) Ledeburite
c) Martensite
d) α-iron
View Answer
Explanation: At room temperature, the most stable form of iron is BCC structure which is also called as α-iron.
8 - Question
When steel with exactly 0.8% carbon by weight is cooled, the FCC structure of the mixture tries to revert back to its BCC structure.
a) True
b) False
View Answer
Explanation: The above statement is true. When steel with exactly 0.8% carbon by weight is cooled, the FCC structure of the mixture tries to revert back to its BCC structure.
9 - Question
Adding a nickel to the steel alloy increases its tensile strength.
a) True
b) Fasle
View Answer
Explanation: The above statement is true. Nickel is added to the steel alloy to increase its tensile strength and make its austenite structure more stable.
10 - Question
Which of the following can be the density of steel?
a) 8.1 g/cm3
b) 7.8 g/cm3
c) 7.7 g/cm3
d) 8.2 g/cm3
View Answer
Explanation: The density of steel varies between 7.75 g/cm3 and 8.05 g/cm3. As only 7.8 g/cm3 lies in that range and the others are beyond the range, 7.8 g/cm3 is the correct answer.