Welcome To My School Study
Practice Class 10 Science MCQs on oxalic acid, Tyndall effect, carbon valency, vestigial organs, electric bulbs, chemistry, physics, biology, NCERT science, and board exam preparation with detailed explanations.
Do You Know
Q1. Which acid is present in tomato?
Correct Answer: Oxalic acid
Detailed Explanation:
Tomato naturally contains Oxalic acid, which is one of the organic acids found in many fruits and vegetables. Organic acids are naturally occurring compounds that contribute to the taste, preservation, and chemical properties of food. The slightly sour taste of tomatoes is due to the presence of acids such as oxalic acid and small amounts of citric acid.
Oxalic acid is a weak organic acid represented by the chemical formula H₂C₂O₄. It is also found in spinach, beetroot, cocoa, tea leaves, and several leafy vegetables. In plants, oxalic acid plays a role in metabolism and mineral regulation.
In Class 10 Science, students study naturally occurring acids to understand the difference between mineral acids and organic acids. Organic acids are generally found in plants and food products, while mineral acids such as hydrochloric acid and sulphuric acid are commonly used in industries and laboratories.
Although oxalic acid occurs naturally in food, excessive consumption of foods containing very high levels of oxalates may contribute to kidney stone formation in susceptible individuals. However, tomatoes are considered healthy foods and provide vitamins, minerals, antioxidants, and dietary fiber.
Understanding the sources of naturally occurring acids helps students connect chemistry concepts with everyday life. Questions about acids present in fruits and vegetables are commonly asked in school examinations and competitive tests.
Real-Life Examples:
- Tomatoes contain oxalic acid naturally.
- Spinach is another rich source of oxalic acid.
- Tea leaves also contain oxalic acid.
Important NCERT Points:
- Oxalic acid is an organic acid.
- It occurs naturally in several plants.
- Tomatoes contain oxalic acid.
- Organic acids contribute to the taste of foods.
Exam-Oriented Fact:
Oxalic acid is commonly associated with tomatoes and spinach.
Quick Revision Line:
Tomato contains oxalic acid, a naturally occurring organic acid.
Q2. The phenomenon of scattering of light by colloidal particles is called:
Correct Answer: Tyndall Effect
Detailed Explanation:
The Tyndall Effect is the phenomenon in which light gets scattered by colloidal particles present in a medium. A colloid is a mixture in which very small particles remain suspended and do not settle down easily. These particles are large enough to scatter light but small enough to remain dispersed.
When a beam of light passes through a colloidal solution, the path of the beam becomes visible because the suspended particles scatter light in different directions. This scattering allows us to see the light beam clearly.
The Tyndall Effect helps distinguish a colloid from a true solution. In a true solution, particles are extremely small and do not scatter light significantly. Therefore, the path of light remains invisible.
This phenomenon is observed frequently in everyday life. For example, when sunlight enters a dusty room through a small opening, the beam becomes visible because dust particles scatter the light. Similarly, car headlights become visible in fog due to the scattering of light by tiny water droplets.
The Tyndall Effect is an important concept in Class 10 Science because it explains many natural optical phenomena. It also helps students understand the properties of colloids and the behavior of light in different media.
Real-Life Examples:
- Sunlight visible in a dusty room.
- Car headlights visible in fog.
- Projector beams visible in a dark hall.
Important NCERT Points:
- Tyndall Effect occurs in colloids.
- Colloidal particles scatter light.
- The path of light becomes visible.
- True solutions generally do not show the Tyndall Effect.
Exam-Oriented Fact:
The visibility of a light beam in fog is due to the Tyndall Effect.
Quick Revision Line:
Scattering of light by colloidal particles is called the Tyndall Effect.
Q3. What is the valency of Carbon?
Correct Answer: (4)
Detailed Explanation:
Valency refers to the combining capacity of an element. It indicates the number of electrons an atom can gain, lose, or share during chemical bonding. Carbon has an atomic number of 6 and an electronic configuration of 2,4. This means it has four electrons in its outermost shell.
To achieve a stable electronic configuration, carbon requires four more electrons. Instead of gaining or losing four electrons, carbon usually shares electrons with other atoms. Therefore, carbon has a valency of 4, making it a tetravalent element.
The tetravalent nature of carbon is responsible for the formation of a vast number of compounds. Carbon can form strong covalent bonds with itself and other elements such as hydrogen, oxygen, nitrogen, and chlorine. This ability allows carbon to create long chains, branched chains, and ring structures.
Because of this unique property, carbon forms the basis of organic chemistry. Millions of organic compounds, including carbohydrates, proteins, fats, medicines, fuels, and plastics, contain carbon atoms.
The ability of carbon to form four bonds makes it one of the most versatile elements in nature. Understanding carbon’s valency is essential for learning chemical bonding and organic compounds in Class 10 Science.
Real-Life Examples:
- Methane (CH₄) contains carbon with valency 4.
- Carbon forms the backbone of proteins.
- Plastics contain carbon-based compounds.
Important NCERT Points:
- Carbon has four valence electrons.
- Its valency is 4.
- Carbon forms covalent bonds.
- Carbon can form chains and rings.
Exam-Oriented Fact:
Carbon is called a tetravalent element because its valency is four.
Quick Revision Line:
Carbon has a valency of 4 and forms four covalent bonds.
Q4. Which of the following is a vestigial organ in humans?
Correct Answer: Vermiform appendix
Detailed Explanation:
A vestigial organ is a body structure that has lost most or all of its original function through the process of evolution. These organs may have been useful to ancestors but are no longer essential for survival in modern humans.
The vermiform appendix is a small, tube-like structure attached to the large intestine. It is considered a vestigial organ because it does not play a major role in digestion in humans today. Scientists believe that in ancient herbivorous ancestors, a larger appendix may have helped digest cellulose-rich plant material.
As human diets and lifestyles evolved, the digestive system changed, and the appendix gradually lost its original importance. Although modern research suggests that the appendix may help maintain beneficial gut bacteria, it is still regarded as a vestigial structure because humans can live normally without it.
Vestigial organs provide important evidence for evolution. They show how organisms change over time and how structures that were once useful may become reduced or functionless.
Other examples often discussed in biology include wisdom teeth, ear muscles, and the tailbone (coccyx). These structures help scientists understand the evolutionary history of humans.
The study of vestigial organs is an important part of Class 10 Biology and frequently appears in board examinations.
Real-Life Examples:
- Appendix in humans.
- Wisdom teeth.
- Tailbone (coccyx).
Important NCERT Points:
- Vestigial organs have reduced functions.
- Appendix is a vestigial organ.
- They provide evidence for evolution.
- Humans can survive without the appendix.
Exam-Oriented Fact:
The appendix is one of the most commonly cited examples of a vestigial organ.
Quick Revision Line:
The vermiform appendix is a vestigial organ in humans.
Q5. Which gas is filled in electric bulbs to prolong the life of the filament?
Correct Answer: Nitrogen or Argon
Detailed Explanation:
Electric bulbs contain a thin tungsten filament that glows when electric current passes through it. The filament becomes extremely hot and produces light through a process called incandescence.
If ordinary air were present inside the bulb, the hot tungsten filament would react with oxygen and burn quickly. To prevent this, manufacturers fill bulbs with inert gases such as Argon or a mixture of Nitrogen and Argon.
These gases do not react chemically with the filament at high temperatures. They reduce the rate at which tungsten evaporates, thereby increasing the lifespan of the filament. As a result, the bulb can operate for a longer period before the filament breaks.
Argon is commonly used because it is chemically inactive and relatively inexpensive. The use of inert gases improves the efficiency and durability of incandescent bulbs.
Although LED bulbs are now more common due to their energy efficiency, traditional incandescent bulbs remain important for understanding the principles of electricity, heating effects, and filament technology.
This topic combines concepts from chemistry and physics and is frequently asked in Class 10 Science examinations.
Real-Life Examples:
- Incandescent bulbs contain argon gas.
- Tungsten filaments glow to produce light.
- Inert gases increase bulb life.
Important NCERT Points:
- Tungsten is used as the filament.
- Argon and nitrogen are inert gases.
- Inert gases prevent rapid oxidation.
- They increase the life of the filament.
Exam-Oriented Fact:
Argon is the most commonly used inert gas in electric bulbs.
Quick Revision Line:
Electric bulbs are filled with nitrogen or argon to protect the tungsten filament and increase its lifespan.
Related links
- Class 10 Science MCQs with Answers | Biology & Physics
- Class 10 SST MCQs with Answers | Federalism & Freedom
- Class 10 SST MCQs with Detailed Black Soil, Sri Lanka
- Quiz Class 10th Social Science NCERT 26-05-2026
- Quiz Class 10th Social Science, NCERT MCQs 23-05-2026
- Quiz Class 10th Social Science, NCERT MCQs , 22-05-2026
- Quiz Class 10th Social Science, NCERT MCQs , 21-05-2026
- Quiz Class 10th Social Science, NCERT MCQs , 18-05-2026
- Quiz Of Class 10th Science 15-05-2026
- Quiz Class 10th Science 14-05-2026
- Quiz Class 10th Science 13-05-2026
Latest Posts
- NCERT Class 7 Maths Chapter 1 Integers,addition, subtraction
- Class 10 Maths Chapter-1 Real Numbers-Rational numbers-MCQ
- Class9 Maths- Number Systems, decimal expansion, exponents
- Class 8 Maths Chapter 1 Rational Numbers, multiplicative
- Class 10 Maths Chapter 1 Real Numbers MCQ Questions with Solutions
Join Our Other Communities
