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The correct choice is (c) 0.70% to 2.2%

The best I can explain: The amount of CARBON present in STEEL differs. They are CLASSIFIED as high carbon steels, low carbon steels, medium carbon steels and wrought iron and cast iron. High carbon steel has 0.70% to 2.2% of carbon.

Correct choice is (B) Trace to 0.08%

For explanation: Iron and steel can be categorized BASED on the amount of carbon present. Wrought iron CONTAINS trace to 0.08% of carbon. Medium carbon steel contains 0.30% to 0.70% of carbon. CAST iron contains 2.2% to 4.5% of carbon.

The CORRECT option is (c) 0.10% to 0.30%

The BEST explanation: Carbon is an EXTREMELY significant material/substance in STEEL.There are DIFFERENT types of steel based on the amount of carbon present. Low carbon steels have a carbon content of 0.10% to 0.30%. High carbon steel has 0.70% to 2.2% carbon.

The correct option is (b) HIGHER

Easy explanation: Compared to SEVERAL other materials/metals, steel has a much higher fatigue life. Fatigue strength REFERS to the endurance of the METAL when subjected to repeated cycles of stress WITHOUT experiencing breakage.

The correct choice is (a) High-carbon STEEL

Easy explanation: Different types of steel, or steel that differs in its COMPONENTS and concentration of carbon show different PROPERTIES. High-carbon steel is REQUIRED when ductility is not crucial but HARDNESS is important.

Right ANSWER is (C) molybdenum

To EXPLAIN I would SAY: S.A.E 4037 is molybdenum steel. This can be used as a replacement for nickel steel in manufacturing several parts like bolts, pins, terminals and several other kinds of components. It is heated to obtain CERTAIN tensile strength.

Correct CHOICE is (d) 2500°F

Best EXPLANATION: The melting point of steel is usually around 2500° Fahrenheit. The melting POINTS of MATERIALS DIFFER. For example, the melting point of aluminium is 1220°F and that of titanium is around 3272°F.

Correct option is (a) huge

To explain I WOULD say: Steel is basically a combination of different metals that result in different types of PHYSICAL CHARACTERISTICS. It is possible to make an infinite number of steels because iron COMBINES with a huge number of ELEMENTS.

The correct CHOICE is (d) 20

Explanation: Steels are widely used in the aerospace industry and in particular the construction of aircraft. They are used in MAKING brace STRUTS, landing gear, wings ETC. Around 20 types of steels are used.

The correct ANSWER is (c) 26

The best explanation: The ATOMIC number INDICATED the number of protons in the nucleus of an ATOM. The atomic number of STAINLESS steels is twenty-six. The atomic number of aluminium is thirteen and that of titanium is twenty-two.

The CORRECT answer is (b) hardness

The EXPLANATION: MANGANESE has a property commonly known as penetration hardness. This is when the manganese is subjected to heat treatment of large SECTIONS and hardness penetrates to the core instead of being limited to the surface.

The CORRECT answer is (c) DURABLE

The explanation: STEEL is known for being very durable and hence is a very desirable metal to be USED in the construction of STRUCTURES. It is not very costly and it is also widely used in major industries across the world.

Correct OPTION is (c) SULPHUR

Best EXPLANATION: There are certain elements that are good to metal steel while there are some elements that are not good for it. Sulphur is an element that is HARMFUL and is best kept in low quantities. So it is PHOSPHOROUS.

Correct CHOICE is (c) IMPACT

Explanation: STEEL contains a very LOW amount of silicone. Less than 0.3%. The ductility of metal can INCREASE by the addition of a small quantity of silicon. Silico-manganese steels have an advantageous impact resistance.

Correct OPTION is (d) good, ductility

The EXPLANATION is: Steels that contain different LEVELS of carbon exhibit different properties and each type is USED for SPECIFIC applications. Medium carbon steels are used when both good strength and ductility are necessary.

The correct answer is (a) True

For explanation: Steel has several advantageous properties. Specifically, when it COMES to STRENGTH, cost etc. Due to these properties, steel is used in the manufacturing of several STRUCTURES like bridges, BUILDINGS, warehouses etc.

Correct ANSWER is (a) chrome-molybdenum

The explanation is: The chrome-molybdenum steel S.A.E 4130 is used in manufacturing AIRCRAFT parts that are made of sheet and tubing. It is preferred for its GOOD WELDING characteristics and it’s reaction to heat treatment.

Correct option is (c) 55,000 p.s.i

For explanation I would say: The STEEL S.A.E 1025 is also called mild carbon steel and cold-rolled stock. It has an ULTIMATE tensile strength of 55,000 p.s.i. It is bought cold-rolled for aircraft manufacturing purposes. It DEVELOPS a higher strength when HEAT treated.

The correct answer is (c) deoxidize

For explanation: MANGANESE is a useful element for steel. It PARTICULARLY HELPS in deoxidizing and desulphurizing the material. This makes the METAL tough. It also helps in the forging process of metal steel.

Right option is (a) less, higher amount

Explanation: There are several factors that are considered while choosing the METAL that has to be USED in the construction of COMPONENTS of an aircraft. Materials requiring less heat treatment are TYPICALLY preferred.

Right choice is (a) True

The explanation: The above statement is true. Chromium is a very advantageous material that GIVES hardness, STRENGTH and CORROSION RESISTANCE to steel when it is added to it. Combining it with nickel also results in good properties.

The CORRECT answer is (d) 7.92 gm. Per c.c

Explanation: Density is the ratio of mass to VOLUME of a substance or OBJECT. The density of stainless STEEL is AROUND 7.92 gm. Per c.c. 4.5 gm. Per c.c is the density of titanium and 2.8 gm. Per c.c is the density of aluminium.

Right option is (d) 14% to 18%

Best explanation: Tungsten STEELS typically have no use in direct components of an aircraft. But, tungsten chromium steels are utilized in MAKING tools. These steels contain 14% to 18% of tungsten and 2% to 4% chromium.

The correct choice is (b) False

For explanation I would say: The above STATEMENT is incorrect. Vanadium is very expensive, especially compared to other alloying ELEMENTS. It is USED in very low quantities but is known to improve the strength of the material.

The correct choice is (C) hardness

Explanation: Addition of carbon in a substance changes its properties. When the amount of carbon present in a material increases, its hardness ALSO increases. DUCTILITY, IMPACT resistance and WELDABILITY decrease.

Correct CHOICE is (b) 1

For EXPLANATION I would say: An extra quantity that is not required of more than one percent can make the MATERIAL extra BRITTLE. Manganese is advantageous when added in the right AMOUNT. It is also none magnetic in nature.

The CORRECT choice is (c) Austenitic manganese steel

To explain: Austenitic manganese steel is CALLED Hadfield’s manganese steel. It is a highly tough material. The material is also EXCEEDINGLY difficult to MACHINE. It also has good RESISTANCE to wear.

Correct choice is (c) Hy-Tuf

Easiest explanation: Hy-Tuf (trade name) is extensively used in the construction of an aircraft, SPECIFICALLY hooks and landing GEAR components. These parts require high tensile strength. These steels should be PROCESSED with GREAT care.

The CORRECT CHOICE is (d) 3 to 5

The BEST explanation: Steels made of nickel contain around three to five percent of nickel. Nickel is a WHITE colored metal and is malleable and ductile in its original pure STATE. Adding the element nickel heightens strength and hardness.

The correct answer is (a) True

Explanation: The above statement is correct. “Red HARDNESS” of tungsten steels is an advantageous property. It means that this tungsten CHROMIUM STEEL used in TOOLS when heated to dull REDNESS tends to keep its cutting edge.

The correct choice is (c) iron, CARBON

For explanation: Steel is a material that is made by combining several metals to obtain several types of PHYSICAL characteristics. Primarily, both iron and carbon are important for this process along with other ELEMENTS in minute QUANTITIES.

Correct answer is (b) toughness

Easiest explanation: Carbon COMBINES readily with iron and is a very important COMPONENT of steel. As the amount of carbon in a SUBSTANCE increases, its toughness DECREASES. Ultimate STRENGTH, hardness and range of heat treatment increase.

The correct choice is (b) False

To explain I would say: The above statement is incorrect. Vanadium alloys are used in very small quantities. It is very expensive. Vanadium alloys or specifically the frequently used chrome-vanadium steel generally possess AROUND 1% chromium. They have HIGH STRENGTH.

Correct choice is (b) HIGH

Easiest explanation: CHROMIUM is an ELEMENT that has a high melting point. It is a hard grey METAL. It is a desirable element as it gives strength, magnetic QUALITY, wear resistance, hardness and corrosion resistance.

The correct choice is (d) CARBON

The best I can EXPLAIN: Steels are used in the construction of DIFFERENT components and tools of an aircraft. Mild carbon steel, also called as cold-rolled stock is used to manufacture some standard parts that also includes aircraft NUTS.

Correct ANSWER is (a) True

The best explanation: The above statement is true. In order to properly classify and GAUGE the composition of the substance, this numerical system can be useful. It CONTAINS NUMBERS and alphabets that represent DIFFERENT qualities.

Correct choice is (c) chromium

Best explanation: The steels that are RESISTANT to corrosion are made with high amounts of chromium. They also tend to be non-magnetic in nature with a few EXCEPTIONS. Chromium can also be COMBINED with other metals to FORM alloys.