Question 1
A ____________ process is carried out to get aluminium from the oxide alumina.
A. electrolytic
B. dynamite
C. chromatography
D. bakelite
View Answer
Answer: Option A
Explanation:
Aluminium is often found in the ore bauxite. But, it is found along with a lot of impurities. Therefore, a chemical process purifies it to alumina after which it is subjected to an electrolytic process.
Question 2
Aluminium alloys also have a system that indicates temper.
A. True
B. False
View Answer
Answer: Option A
Explanation:
Aluminium alloys have a system of designation that is denoted by four digits. The four digits are followed by the temper designation. It consists of the letters O, F, H and T after which there is a number. They represent annealed, fabricated and strain hardened respectively.
Question 3
Aluminium alloys are used for constructing very few parts in an aircraft due to lack of availability.
A. True
B. False
View Answer
Answer: Option B
Explanation:
The above statement is incorrect. Aluminium alloys are materials with lots of advantages. They are used extensively in building an aircraft. The structure of the aircraft and wing beams are also manufactured using aluminium alloys.
Question 4
Aluminium alloys can be categorized into Cast and ___________ alloys.
A. extrusions
B. heat treatable
C. non-heat treatable
D. wrought
View Answer
Answer: Option D
Explanation:
Aluminium alloys are alloys where aluminium is present in a higher amount. It can be roughly categorized into two categories. Cast alloys and wrought alloys. Both the categories can again be divided into heat-treatable and non-heat treatable.
Question 5
Pitting of the surface is a kind of aluminium alloy __________
A. corrosion
B. annealing
C. strength
D. manufacturing method
View Answer
Answer: Option A
Explanation:
One of the most important factors to consider while dealing with materials is corrosion. Aluminium alloys can be painted with a coating to avoid it. Pitting of the surface is corrosion that affects the surface due to the existence of moisture.
Question 6
The aluminium association has a designation system for aluminium alloys which are denoted by __________ digits.
A. 23
B. 2
C. 9
D. 4
View Answer
Answer: Option D
Explanation:
The aluminium association has a designation system for aluminium alloys that are denoted by four digits. The four digits of numbers represent different parameters of the material, aluminium alloys.
Question 7
The final two digits in the nomenclature of aluminium alloys represent aluminium __________
A. impurity
B. group
C. purity
D. strength
View Answer
Answer: Option C
Explanation:
The nomenclature of aluminium alloys was made by the aluminium association to avoid confusion. It consists of 4 digits that represent various parameters. The last two digits indicate aluminium purity.
Question 8
The melting point of aluminium is ___________
A. 236°c
B. 1085°c
C. 660°c
D. 1510°c
View Answer
Answer: Option C
Explanation:
The melting point of aluminium is 660°c. Aluminium alloys are subjected to different temperatures during heat treatment. The melting point of copper is 1085°c. The melting point of steel is 1510°c.
Question 9
The primary commercial source for aluminium is ____________
A. coal
B. bauxite
C. magnetite
D. pyrite
View Answer
Answer: Option B
Explanation:
Aluminium can be obtained from several sources. For example, it is found in several clays and rocks. But the primary source for aluminium is bauxite ores. Bauxite contains aluminium and some impurities.
Question 10
Aluminium is __________
A. non-magnetic
B. ductile
C. magnetic
D. non-magnetic and ductile
View Answer
Answer: Option D
Explanation:
Aluminium is a soft material. It is silvery-white in colour. It has a melting point of around 660°c. It is also both non-magnetic and ductile in nature. The atomic number of the element aluminium is 13.
Question 11
Aluminium weighs around __________ of steel.
A. 2 times
B. 1/2
C. 1/3
D. 4 times
View Answer
Answer: Option C
Explanation:
One of the most important advantages of aluminium is its weight. Aluminium weighs less than steel. But steel is stronger compared to aluminium. Steel weighs almost three times the weight of aluminium.
Question 12
Which of the following is not a common property for all aluminium alloys?
A. Low strength
B. Heat treatable
C. Easy for machining
D. Readily joined be welding
View Answer
Answer: Option A
Explanation:
Aluminium alloys are good materials to use in the aerospace industry. They are heat treatable, can readily be joined by welding, soldering and are easy to machine. They also have high strength.
Question 13
Which of the following is not an aluminium alloy?
A. Al-Si
B. Al-Zn
C. Al-Mn
D. Al-U
View Answer
Answer: Option D
Explanation:
Aluminium alloys are alloys where aluminium is present in a higher amount. Aluminium alloys can be made with aluminium and zinc, aluminium and manganese, aluminium and silicon, etc. Uranium is a radioactive material.
Question 14
Why has the aluminium association established a system of designating aluminium alloys?
A. To create employment
B. To remove confusion
C. To encourage research
D. To ensure availability
View Answer
Answer: Option B
Explanation:
The aluminium association has made this system to remove confusion. The confusion was caused due to companies having different numbering systems for aluminium materials of similar chemical composition.