Science & Technology › Materials & Engineering – UPSC Prelims PYQs

Which of the following statements with regard to Black Boxes used in modern aircrafts is/are correct ?

1. They carry a beacon emitting red light pulses to facilitate underwater detection.
2. They record both the cockpit voice and flight data.
3. Their memory units are made using either stainless steel or titanium.

Select the answer using the code given below :

Consider the following statements :

Statement I : Some rare earth elements are used in the manufacture of flat television screens and computer monitors.

Statement II : Some rare earth elements have phosphorescent properties.

Which one of the following is correct in respect of the above statements?

In which of the following are hydrogels used ? 1. 2. 3.

Select the correct answer using the code given below :

Consider the following statements :

1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts.
2. Carbon fibres once used cannot be recycled.

Which of the statements given above is/are correct?

With reference to India, consider the following statements :

1. Monazite is a source of rare earths.
2. Monazite contains thorium.
3. Monazite occurs naturally in the entire Indian coastal sands in India.
4. In India, Government bodies only can process or export monazite.

Which of the statements given above are correct ?

With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements :

1. Its fibres can be blended with wool and cotton fibres to reinforce their properties.
2. Containers made of it can be used to store any alcoholic beverage.
3. Bottles made of it can be recycled into other products.
4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.

Which of the statements given above are correct ?

Consider the following statements :

1. Other than those made by humans, nanoparticles do not exist in nature.
2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics.
3. Nanoparticles of some commercial products which enter the environment are unsafe for humans.

Which of the statements given above is/are correct ?

With reference to carbon nanotubes, consider the following statements :

1. They can be used as carriers of drugs and antigens in the human body.
2. They can be made into artificial blood capillaries for an injured part of human body.
3. They can be used in biochemical sensors.
4. Carbon nanotubes are biodegradable.

Which of the statements given above are correct ?

"3D printing" has applications in which of the following ?

1. Preparation of confectionery items
2. Manufacture of bionic ears
3. Automotive industry
4. Reconstructive surgeries
5. Data processing technologies

Select the correct answer using the code given below :

There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why?

1. They can accumulate in the environment, and contaminate water and soil.
2. They can enter the food chains.
3. They can trigger the production of free radicals.

Select the correct answer using the code given below.

Graphene is frequently in news recently. What is its importance?

1. It is a two-dimensional material and has good electrical conductivity.
2. It is one of the thinnest but strongest materials tested so far.
3. It is entirely made of silicon and has high optical transparency.
4. It can be used as 'conducting electrodes' required for touch screens, LCDs and organic LEDs.

Which of the statements given above are correct?

Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why?

1. China, which is the largest producer of these elements, has imposed some restrictions on their export.
2. Other than China, Australia, Canada and Chile, these elements are not found in any country.
3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements.

Which of the statements given above is/are correct?

What are Rubies and Sapphires chemically known as?

Consider the following statements:

1. The series of international paper sizes is based on A0 size whose area is 0.5 m² (approx).
2. The area of A4 size paper is 1⁄8th of the A0 size paper.

Which of the statements given above is/are correct?

Which one of the following types of glass can cut off ultraviolet rays?

Assertion (A): Cellulose is used in making shatter-proof glass.

Reason (R): Polysaccharides are not soluble in water.

Which are the materials generally employed as solder in soldering operation in electronics?

Which one of the following is the correct sequence of the given substances in the decreasing order of their densities?

Standard 18-carat gold sold in the market contains

Which one of the following materials is very hard and very ductile?

Aluminium surfaces are often “anodized”. This means the deposition of a layer of

Match List I (Naturally occurring substances) with List II (Elements) and select the correct answer using the codes given below the Lists:

List I I. Diamond II. Marble III. Sand IV. Ruby

List II A) Calcium B) Silicon C) Aluminium D) Carbon

Codes:

Consider the following statements:

I. Glass can be etched or scratched by diamond. II. Glass can be etched or scratched by hydrofluoric acid. III. Glass can be etched or scratched by aqua regia. IV. Glass can be etched or scratched by concentrated sulphuric acid.

Which of these statements are correct?

Consider the following statements: Coke is one of the materials of the charge added to blast furnace for the production of steel/iron. Its function is to I. Act as a reducing agent. II. Remove silica associated with the iron ore. III. Function as fuel, to supply heat. IV. Act as an oxidizing agent. Of these statements:

Which one of the following elements is alloyed with iron to produce steel which can resist high temperatures and also have high hardness and abrasion resistance?

Which one of the following polymers is widely used for making bullet-proof material?