Percentage Composition MCQ Quiz in मल्याळम - Objective Question with Answer for Percentage Composition - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

The correct answer is Lead and Tin.

Key Points

• Solder is an alloy primarily made of Lead (Pb) and Tin (Sn).
• The typical composition of solder is 60% Tin and 40% Lead, though variations exist depending on the application.
• Solder has a low melting point, usually in the range of 180°C to 190°C, making it ideal for joining electrical wires and components.
• It is widely used in electronics and electrical engineering for creating strong and conductive bonds between metal surfaces.
• Lead-Tin solder is preferred for its good wettability, mechanical strength, and electrical conductivity.

Additional Information

• Lead (Pb):
  • A soft, malleable metal with a low melting point of 327.5°C.
  • It is used in solder to lower the melting temperature and improve the alloy's flow characteristics.
• Tin (Sn):
  • A silvery metal with a melting point of 231.9°C.
  • It is the primary component in solder, providing strength and corrosion resistance.
• Applications of Solder:
  • Used in printed circuit boards (PCBs) and electrical connections.
  • Also applied in plumbing, jewelry making, and metalwork.
• Lead-Free Solder:
  • Due to health and environmental concerns, lead-free solder (e.g., Tin-Silver-Copper alloys) is increasingly used.
  • However, lead-free solder typically has a higher melting point and different mechanical properties.
• Soldering Flux:
  • A chemical agent used alongside solder to prevent oxidation and improve the flow of solder.
  • Flux ensures a clean and strong bond between metal surfaces.

The correct answer is Copper and Zinc.

Key Points

• An alloy is a substance which is formed when two or more metals are combined. They can also be formed when metals are combined with other elements. 
  • The properties that alloys exhibit differ from the individual properties of these elements; when you compare them to pure metals, they are stronger and harder.
• Metals are generally malleable, and ductile. Most pure metals are either very brittle, soft or chemically reactive to be practically used.
• When different ratios of metals are combined as alloys, it modifies the original properties of metals to give desirable characteristics.
  • Alloys are generally made to keep them less brittle, corrosion-resistant, harder, or even have a more desirable lustre and colour.
• Brass is a very useful alloy of Copper in which the quantity of Copper (Cu) is 70% and Zinc (Zn) is 30%. Hence option 2 is correct.
• Brass alloys have great strength, durability and machinability as compared to normal copper.
  • Also, their melting point is lower than Copper (Cu) and Zinc (Zn). These alloys are also corrosion, water resistant and have a good lifespan.
  • Brass is used in Household utensils, idols, making jewellery, forgings, rivets, screws etc.

Additional Information

• Bronze is an alloy made up of 90% Copper (Cu) and 10% Tin (Sn).
  • It is used in household utensils, bells, coins etc.
  • Bronze is much superior compared to pure copper when it comes to hardness and is also more ductile and machineable compared to pure copper.
• Rolled gold or artificial gold is a famous alloy of Copper (Cu) at 90% and Aluminium (Al) at 10%.
  • It is utilized in making cheap ornaments. Aluminium is known for making a number of alloys.
• Copper (Cu) and Iron (Fe) master alloys are used as a grain refiner for some brass alloys and aluminium bronze.
  • It is also used for improving the mechanical properties of low alloyed coppers and the corrosion resistance of copper-nickel alloys.

The correct answer is 0.80% Oxygen.

• The sun's mass is made up of around 0.80% Oxygen.

Key Points

• Composition of the sun:
  • 73% of the Sun’s mass is hydrogen, and another 25% is helium. 
  • The Sun and the stars are made up of mostly hydrogen and helium.
  • It was first shown in a thesis in 1925 by Cecilia Payne-Gaposchkin.
  • The core is approximately 20% of the size of the solar interior and has a temperature of approximately 15 million K.
  • It generates its energy by nuclear fusion of hydrogen nuclei into helium.
  • The inner layers are the Core, Radiative Zone and Convection Zone.
  • The outer layers are the Photosphere, the Chromosphere, the Transition Region and the Corona.

Additional Information

• Solar Missions:
  • Genesis was the first solar mission and spacecraft to capture a sample of the solar wind.
  • Aditya-L1 is the first solar mission of India to study the Sun.
  • NASA’s Parker Solar Probe is the first mission to touch the Sun.

The correct answer is 0.1 - 2% carbon.

Key Points

• Steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and trace amounts of silicon, phosphorus, sulphur and oxygen.
• The steel Melting Process was invented by Bessemer.
• Stainless Steel was invented by Harry Brearley.

Additional Information

• Alloy: It is a solid-solid mixture of two or more metals and non-metal.
  • Alloy enhances the property of a particular metal.
• Some other important alloys are: