Metals and Properties MCQ Quiz - Objective Question with Answer for Metals and Properties - Download Free PDF
Last updated on Apr 3, 2025
Latest Metals and Properties MCQ Objective Questions
Metals and Properties Question 1:
The alloy of copper and zinc is _______.
Answer (Detailed Solution Below)
Metals and Properties Question 1 Detailed Solution
Explanation:
Alloy:
- An alloy is a substance formed from the combination of two or more metals.
- Alloys can also be formed from combinations of metals and other elements.
- In simpler words, an alloy can be defined as a homogeneous mixture of two or more metals or a metal and a non-metal.
- Brass is an alloy of copper and zinc. The percentage of copper (Cu) and zinc (Zn) is (Cu = 60-80% Zn = 40-20%).
- German silver is a term for various Copper, Zinc, and Nickel alloys, often even containing Lead and Tin.
- German silver is also known as Nickel silver and has the main component Copper with varying quantities of Nickel and Zinc.
- German silver is widely used because of its hardness, toughness, and resistance to corrosion.
- Bronze is an alloy of copper, zinc, and tin.
- Solder is an alloy of lead and zinc.
- Gunmetal is composed of 88 percent copper, 10 percent tin, and 2 percent zinc and is used for gears and bearings that are to be subjected to heavy loads and low speeds.
Metals and Properties Question 2:
Typical percentage (%) of Tungsten in HSS Tool material is _______.
Answer (Detailed Solution Below)
Metals and Properties Question 2 Detailed Solution
Explanation:
High-Speed Steel:
- It is an alloy tool steel that retains much of its hardness and toughness at red heat after heat treatment, allowing tools made of it to cut at high speeds even while red-hot through friction.
- High-speed steels (HSS ) get their name from the fact that they may be operated as cutting tools at much higher cutting speeds than is possible with plain carbon tool steels.
- High-speed steels operate at cutting speeds 2 to 3 times higher than carbon steels.
- A common type of high-speed steel contains 18% tungsten, 4% chromium, 1% vanadium, and only 0.5–0.8% carbon.
Types of High-Speed Steel:
18-4-1 High-Speed Steel:
- This steel, containing 18 percent tungsten, 4 percent chromium, and 1 percent vanadium with about 0.75 percent carbon is considered to be one of the best all-purpose tool steels.
- This steel is extensively used for lathe, planer, and shaper tools, drills, and milling cutters.
Cobalt High-Speed Steel:
- This is known as super high-speed steel.
- Normally cobalt is added from 5 to 8 percent to increase better hot hardness and wear resistance than the 18 : 4: 1 type.
- One analysis of cobalt high-speed steel contains 20 percent tungsten, 4 percent chromium, 2 percent vanadium, and 12 percent cobalt.
- The addition of cobalt increases heat resistance and can give a Rockwell hardness of up to 70 Min.
Vanadium High-Speed Steel:
- This steel contains 0.70 percent carbon and more than 1 percent vanadium.
- High vanadium with carbon high-speed steel is superior to the 18:4:1 type for difficult-to-machine materials.
- This has excellent abrasive resistance.
Molybdenum High-Speed Steel:
- This steel containing 6 percent molybdenum, 6 perc tungsten, 4 percent chromium, and 2 percent vanadium has excellent toughness and cutting ability.
- Combining molybdenum, tungsten, and chromium steel creates several alloys commonly called “HSS“, measuring 63–65 Rockwell “C” hardness.
Metals and Properties Question 3:
Cast iron is used for machine bodies due to its following property:
Answer (Detailed Solution Below)
Metals and Properties Question 3 Detailed Solution
Explanation:
Cast iron:
- Cast iron is a high-carbon alloy of iron with carbon. It usually contains alloy additives such as silicon, manganese, phosphorus, or sulfur also.
- Cast iron contains from 2.06 to 6.67% carbon in the form of cementite or graphite.
- The occurrence of a particular phase of carbon depends on the cooling rate and chemical composition of the alloy.
- One of the types of cast iron is gray cast iron wherein the carbon is present as graphite.
- It is regarded as cast iron of higher quality and is more ductile, easily treatable, has good fluidity, and has a smaller shrinkage casting (around 1.0%) than white cast iron.
- It is used to make bodies, housings, blocks of pumps, compressors, and motors although it is more brittle and susceptible to cracking than steel.
- Grey cast iron is used because of having exceptional damping Capacity (the relative ability of a material to absorb shock or vibration).
- Grey cast iron possesses this property due to the presence of carbon in the form of graphite flakes in the pearlite/ferrite matrix.
- The morphology of graphite as a flake in grey cast iron enables it to absorb both compressive and vibrational loads without initiating a crack.
- In general, vibration can be critical in machinery and can cause an unsatisfactory operation or even failure.
Metals and Properties Question 4:
Which one of the following contains higher percentage of carbon?
Answer (Detailed Solution Below)
Metals and Properties Question 4 Detailed Solution
Explanation:
Wrought iron
- Wrought iron is a very pure iron where the iron content is of the order of 99.5%.
- It usually contains less than 0.1% carbon and 1 or 2% slag.
- It is produced by re-melting pig iron and some small amount of silicon, sulphur, or phosphorus may be present.
- It is tough, malleable and ductile and can easily be forged or welded.
- It cannot however take sudden shock. Chains, crane hooks, railway couplings and such other components may be made of this iron.
Pig iron
- Pig iron is an intermediate product of the iron industry.
- Pig iron has a very high carbon content, typically 3.8–4.7%, along with silica and other constituents of dross, which makes it very brittle, and not useful directly as a material except for limited applications.
Cast iron
- Cast iron is an alloy of iron, carbon and silicon and it is hard and brittle.
- Carbon content in CI may be within 1.7% to 3% and carbon may be present as free carbon or iron carbide Fe3C.
- In general, the types of cast iron are (a) grey cast iron and (b) white cast iron (c) malleable cast iron etc
Steel
- Steel is basically an alloy of iron and carbon in which the carbon content can be less than 1.7% and carbon is present in the form of iron carbide to impart hardness and strength.
- Two main categories of steel are (a) Plain carbon steel and (b) alloy steel.
- Thus, cast iron contains higher percentage of carbon
Metals and Properties Question 5:
The metal always found in the free state is ____________.
Answer (Detailed Solution Below)
Metals and Properties Question 5 Detailed Solution
The correct answer is Au.
- Most of the metals are very reactive and unstable.
- Gold (Au) is often found in a free state.
Key Points
- It is an element of noble quality, due to which its compounds are usually temporary.
- It is distributed in very small amounts in igneous rocks but over time its quantity has increased in quartz veins.
- Gold is a metal and element.
- Pure gold is a bright yellow colour and used for making coins, jewellery, and is a collection of money since ancient times.
- Chemically, it is an element with the symbol Au and atomic number 79.
- It is an inert metal.
Top Metals and Properties MCQ Objective Questions
Temple bells are made of metals because they are:
Answer (Detailed Solution Below)
Metals and Properties Question 6 Detailed Solution
Download Solution PDFThe correct answer is Sonorous.
Key Points
- A sonorous is a substance which is capable of producing sound. Metals are generally sonorous they produce sound on being struck or hit by something.
- The physical property of the metal produced a ringing sound when it strikes on a hard surface is called sonority, hence the temple bells or school bells are made up of sonorous metals.
Additional Information
- Ductile is a material that is able to draw out into thin wire and deformed without losing its toughness.
- Malleable is a material able to be pressed or hammered into shape without cracking or breaking.
Gold and copper happen to absorb ______ and violet light, leaving yellow light.
Answer (Detailed Solution Below)
Metals and Properties Question 7 Detailed Solution
Download Solution PDFThe correct answer is blue.
Key Points
- Gold and copper happen to absorb blue and violet light, leaving yellow light in the spectrum.
- So gold and copper are yellowish in colour.
- The only two non-silvery metals in the world are gold and copper.
- A metal is defined as an element that readily forms positive ions (cations) and has metallic bonds.
- These elements have electrons that are loosely held to the atoms, and will readily transfer them.
- Most metals' electrons reflect all colours equally which are in the visible spectrum of light.
- So those metals appear as white silver.
Which of the following metals is the purest form of iron?
Answer (Detailed Solution Below)
Metals and Properties Question 8 Detailed Solution
Download Solution PDFExplanation:
Wrought iron
- It is a very pure iron where the iron content is of the order of 99.5%.
- It is produced by re-melting pig iron and some small amount of silicon, sulphur, or phosphorus may be present.
- It is tough, malleable and ductile and can easily be forged or welded.
- It cannot however take sudden shock.
- Chains, crane hooks, railway couplings and such other components may be made of this iron.
Additional Information
Cast iron
- It is an alloy of iron, carbon and silicon and it is hard and brittle.
- Carbon content in CI may be within 1.7% to 3% and carbon may be present as free carbon or iron carbide Fe3C.
- In general, the types of cast iron are (a) grey cast iron and (b) white cast iron (c) malleable cast iron, etc.
Grey Cast Iron:
- The presence of graphite gives a grey shade to the fractured surface of cast iron. Therefore, when all the carbon in cast irons is in the form of graphite, it is called Grey cast Iron.
- Grey cast iron with a carbon content of 2.4% - 3.8%.
- In general, a higher percentage of graphite reduces the mechanical properties of cast iron.
- A lower percentage of graphite makes the cast iron difficult to cast.
- Other elements present in grey cast iron are silicon, manganese, sulphur and phosphorous which impart machinability, weldability, and corrosion resistance.
White Cast Iron:
- The presence of cementite gives a shiny light coloured surface to fractured cast iron. Therefore, cast irons which have all the carbon in the form of cementite are called White cast iron.
- It is obtained by the rapid cooling of molten alloy which is also known as chilled cast iron.
- It is extremely hard and brittle.
- Its hardness ranges between 400 - 500 BHN.
The part of ship that always remains under water _________.
Answer (Detailed Solution Below)
Metals and Properties Question 9 Detailed Solution
Download Solution PDFThe correct answer is rusts faster because it is salt water.
Key Points
- Ships are made of iron and a part of them remains underwater.
- On the part above water also water drops keep clinging to the ship’s outer surface.
- Moreover, the water of the sea contains many salts.
- The saltwater makes the process of rust formation faster.
- Therefore, ships suffer a lot of damage from rusting in spite of being painted.
- Stainless steel is made by mixing iron with carbon and metals like chromium, nickel, and manganese.
- It does not rust.
Additional Information
- Iron is used in making bridges, ships, cars, truck bodies, and many other articles, the monetary loss due to rusting is huge.
- The process of rusting can be represented by the following equation:
- Iron (Fe) + Oxygen (O2, from the air) + water (H2O) → Rust (iron oxide Fe2O3)
- For rusting, the presence of both oxygen and water (or water vapour) is essential.
The metal is _______ in its original state.:
Answer (Detailed Solution Below)
Metals and Properties Question 10 Detailed Solution
Download Solution PDFThe correct answer is As a mixture with gourd-metal.
Key Points
- Metal is very reactive and unstable. In surroundings, they react with other elements to form compounds to attain stability.
- Metals thus react with sulfides, carbonates, oxygen to form respective minerals.
- Hence they do not occur in the free state.
- The metals that can be found in the free state in nature are gold, silver, platinum, etc.
- Because they are non-reactive metals.
Hint
- A native metal is any metal that is found pure in its metallic form in nature.
- Only gold, silver, copper, and the platinum group occur natively in large amounts.
Which of the following is combined to form Solder?
Answer (Detailed Solution Below)
Metals and Properties Question 11 Detailed Solution
Download Solution PDFThe correct answer is Lead and tin.
- Solder is a metal alloy usually made of tin (60%) and lead (40%) which is melted using a hot iron.
- Soldering is a joining process used to join different types of metals together by melting solder.
Important Points
- List of Important Alloys and their Uses:
ALLOY COMPOSITIONS USES Brass Cu + Zn Making of utensils. Bronze Cu + Sn Making of coins, bell, and utensils. German Silver Cu + Zn + Ni Making of utensils Gun Metal Cu + Sn + Zn + Pb Making of guns, barrels, gears, and bearings. Stainless steel Fe + Cr + Ni + C Making of utensils and surgical cutlery. Nickel steel Fe + Ni Making of electrical wire, automobile parts.
The mineral named ‘Calaverite’ is a telluride mineral containing :
Answer (Detailed Solution Below)
Metals and Properties Question 12 Detailed Solution
Download Solution PDFThe correct answer is gold.
Key Points
- Calaverite, also known as gold telluride, is a rare gold telluride, a metallic mineral with the chemical formula AuTe2, in which about 3% of the gold is replaced by silver.
- In 1861, it was discovered in Calaveras County, California, and in 1868, it was named after the county.
- The mineral's colour can range from silvery white to brassy yellow and has a metallic shine.
- It is similar to the gold-silver telluride mineral sylvanite, although it contains substantially more silver.
- Krennerite is another AuTe2 mineral with a distinct crystal structure.
- The principal gold telluride ores are calaverite and sylvanite, albeit such ores are often small gold sources.
Important Points
- Gold is a naturally occurring chemical element with the symbol Au and atomic number 79, making it one of the higher atomic number elements.
- In its pure state, it is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal.
- Gold is a transition metal and a group 11 element chemically. It is a non-reactive chemical element that is solid under normal conditions.
- In rocks, veins, and alluvial deposits, gold is frequently found in its free elemental (native) form as nuggets or grains.
- It can be found in solid solution with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions like pyrite.
Which of the following metals exist in their original state?
Answer (Detailed Solution Below)
Metals and Properties Question 13 Detailed Solution
Download Solution PDFThe correct answer is Platinum.
Key Points
- Platinum metals exist in their original state.
- Platinum is a chemical element with the symbol Pt and atomic number 78.
- It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal.
- Its name is derived from the Spanish term platino, meaning "little silver"
- Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements.
- Platinum is one of the least reactive metals.
- The white silver metal known as platinum is the heaviest of the precious metals, weighing almost twice as much as karat gold.
Additional Information
- Copper is a chemical element with the symbol Cu and atomic number 29.
- It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
- A freshly exposed surface of pure copper has a pinkish-orange color.
- Copper is used as a conductor of heat and electricity.
- Iron is a brittle, hard substance, classified as a metal in Group 8 on the Periodic Table of the Elements.
- The most abundant of all metals, its pure form rapidly corrodes from exposure to moist air and high temperatures.
- It is the fourth most widely distributed element on the earth's crust but is found as iron ore rather than as a useable metal.
- Iron ore comes in a variety of forms and looks like a rock.
- It is a mixture of iron, oxygen, and other elements, mixed in with sands and clays.
- Potassium is a chemical element with the symbol K and atomic number 19.
- Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force.
- Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure.
Which of the following material, the outer part of a holding jaw of in a bench vice is made up of?
Answer (Detailed Solution Below)
Metals and Properties Question 14 Detailed Solution
Download Solution PDFExplanation:
- Vices are used for holding the workpieces. They are available in different types.
- The vice used for bench work is the bench vice or called Engineer’s vice.
- A bench vice is made of cast iron or cast steel and it is used to hold work for filing, sawing, threading, and other hand operations.
- A bench vice handle has Square type of threads.
- The size of the vice is stated by the width of the jaws. e.g. 150 mm parallel jaw bench vice
Bearing bushes are made up of ________
Answer (Detailed Solution Below)
Metals and Properties Question 15 Detailed Solution
Download Solution PDFExplanation:
A bushed bearing, is an improved solid bearing in which a bush of brass or gun metal is provided.