Q171. Bakelite and melamine are examples of which type of polymer?
Basics of Everyday Science: RAS Prelims MCQs
200 RAS Prelims MCQs on the basics of everyday science test the scientific method, the laws of motion, chemical bonding and the cell theory. The questions use daily-life examples, such as the recoil of a gun and the orbit of a satellite, and the explanations give the principle behind each example so that you can reason out similar questions.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 171–180 of 200 questions
Q172. The process of heating natural rubber with sulfur to improve its strength and elasticity is called:
Explanation
Vulcanization is a chemical process used to enhance the physical properties of natural rubber. By heating the raw rubber with sulfur, cross-links are formed between the long polymer chains. This modification significantly improves the material’s strength, durability, and elasticity while reducing its tackiness. Vulcanized rubber is resistant to temperature changes, making it suitable for manufacturing tires, hoses, and industrial products.
Q173. Which of the following synthetic fibers is often referred to as "artificial silk" because it is regenerated from natural cellulose?
Explanation
Rayon is a semi-synthetic fiber produced by chemically regenerating natural cellulose, typically sourced from wood pulp or cotton linters. Because it possesses a lustrous appearance and smooth texture similar to natural silk but is much more affordable, it is commonly referred to as "artificial silk." Rayon is highly versatile and is widely used in the textile industry for clothing and upholstery.
Q174. Brass is an alloy primarily composed of which two metals?
Explanation
Brass is a versatile metallic alloy primarily composed of copper and zinc. By varying the proportions of these two metals, manufacturers can create different types of brass with specific mechanical and electrical properties. It is widely used in musical instruments, decorative hardware, and plumbing fixtures due to its attractive gold-like appearance, excellent workability, and high resistance to corrosion and wear.
Q175. Bronze is a historically significant alloy made mostly of:
Explanation
Bronze is a historically significant alloy that consists primarily of copper, with tin as the main additive. Other elements may be added to enhance specific properties. Bronze is harder and more durable than pure copper and is highly resistant to corrosion, especially from seawater. This made it the preferred material for ancient tools, statues, and modern industrial components like ship propellers.
Q176. Select the correct sequence of the following fibers arranged in increasing order of their typical tensile strength:
Explanation
Tensile strength measures the maximum stress a material can withstand while being stretched. Among these common fibers, wool generally has the lowest tensile strength. Cotton, a natural plant fiber, is significantly stronger than wool. Nylon, a fully synthetic polymer, is engineered for extreme durability and possesses the highest tensile strength of the three, making it ideal for products like ropes and parachutes.
Q177. Kevlar, a high-strength synthetic polymer, is best known for its use in:
Explanation
Kevlar is a high-performance synthetic fiber belonging to the aramid family. It is renowned for its exceptional tensile strength-to-weight ratio, being five times stronger than steel on an equal weight basis. Its unique molecular structure allows it to absorb and dissipate energy from high-velocity impacts, making it the primary material used in the manufacture of bulletproof vests and personal protective equipment.
Q178. Fiberglass is an example of a composite material where glass fibers are embedded in a:
Explanation
Fiberglass is a type of composite material where extremely fine fibers of glass are used as a reinforcement. These fibers are embedded within a liquid polymer matrix, typically a plastic resin, which is then cured into a solid. The resulting material combines the high tensile strength of the glass fibers with the flexibility and lightweight nature of the plastic, creating a durable product.
Q179. The principal raw material used in the manufacture of ordinary glass is:
Explanation
Silica, commonly found in the form of quartz sand, is the fundamental raw material used in the production of ordinary glass. To lower the high melting point of pure silica, other substances like sodium carbonate and limestone are typically added. When heated to high temperatures, this mixture melts into a liquid that, upon cooling, forms the transparent, amorphous solid we know as glass.
Q180. The most abundant chemical compound in Portland cement is:
Explanation
Portland cement is a complex mixture of several chemical compounds, but calcium oxide, also known as lime, is the most abundant constituent, typically making up over sixty percent of its weight. Other important ingredients include silica, alumina, and iron oxide. These compounds are produced by heating a precisely proportioned mixture of limestone and clay in a kiln for construction applications.Answer key for these questions
| Q | Correct answer |
|---|---|
| 171 | (d) Thermosetting plastics |
| 172 | (b) Vulcanization |
| 173 | (c) Rayon |
| 174 | (d) Copper and Zinc |
| 175 | (a) Copper and Tin |
| 176 | (b) Wool < Cotton < Nylon |
| 177 | (b) Bulletproof vests and body armor |
| 178 | (a) Polymer or plastic matrix |
| 179 | (c) Silica (sand) |
| 180 | (d) Calcium oxide (CaO) |
Key facts from Basics of Everyday Science
- Inductive reasoning draws a general conclusion from specific observations; a control variable is kept constant in an experiment; communicating the results is the last step of the scientific method.
- Newton’s second law relates force, mass and acceleration; the recoil of a gun illustrates the third law.
- Momentum is the product of mass and velocity; impulse is equal to the change in momentum.
- A satellite in uniform circular orbit is held by the centripetal force provided by gravity.
- Water (H₂O) and N₂ show covalent bonding; sodium chloride, MgO and CaF₂ are ionic.
- The classical cell theory does not say that all cells have a true nucleus.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Basics of Everyday Science?
This page has 200 practice MCQs on Basics of Everyday Science (Science and Technology). Each has the correct answer, and most have an explanation.
What is the product of mass and velocity called?
Momentum. Newton’s second law says that the rate of change of momentum is equal to the force applied, and impulse is equal to the change in momentum of a body.
Which law explains the recoil of a gun?
Newton’s third law of motion. The gun pushes the bullet forward, and the bullet pushes the gun back with an equal and opposite force, which is felt as recoil.
What holds a satellite in a circular orbit?
The centripetal force provided by gravity. The Earth’s pull keeps changing the direction of the satellite’s velocity so that it moves in a circle and does not fly off in a straight line.