Important question of science class 10

Scientific Study

1. What is scientific learning?

2. Name the fundamental and derived unit.

3. What is the dimension of a physical quantity? Give an example.

4. What is a derived unit? Give two examples.

5. Write the basic unit involved in the following derived units; Joule, Pascal, hertz, Newton

6. Raman wants to investigate which color of an object has the highest capacity to absorb heat. He took four tin cans and painted them with black, white, green, and red colors respectively. He poured an equal amount of water into each can, closed the openings, and placed them in sunlight for an hour. After that, he measured the temperature of the water in each can using a thermometer. Answer the following questions based on this experiment.

  1.  Write the independent and dependent variables.
  2. Which variables should be controlled by Raman? Explain.
  3.  What is the hypothesis of this experiment?
  4.  How will Raman ensure that the temperature measurements are accurate?
  5. How might Raman extend this experiment to test other factors that affect the absorption of heat by an object?

7. Why is the unit of work a derived unit?

8. Analyse the following equations unit-wise to prove whether it is valid or not.

  1. S = ut + $\frac{1}{2}at^2$
  2. $v^2$ - $u^2$= 2a.s

9. Why are independent and dependent variables important in scientific study?

10. Clarify different types of variables giving an example of an experiment.

Classification of Living Beings

1. Who proposed the five-kingdom system of classification?

2. What are chordates and evolution?

3. The spider has four pairs of jointed legs. Which phylum does it belong to?

4. Write the division of the kingdom plantae.

5. Write the importance of classification.

6. Which phylum does include the parasitic animals? Give one example and one character.

7. How are evolution and classification related to each other?

8. Name the classes of vertebrates and give one example of each.

9. Identify the animals on the basis of their salient features and write one more character of each.

  1. The body is covered with a waterproof scale and it respires through the gills.
  2. The body is covered with hair and it can fly.
  3. The body is covered with spiny skin and it moves its tube feet.
  4.  Respiration takes place through the lungs and locomotion with the help of the flippers.

10. Fern is a non-flowering plant while mustard is a flowering plant; both of them are placed in the same division. What is the reason for it?

11. Whales, fish, and crocodiles live in water. Based on their characteristics, write which is the most developed one and which one is the least developed. Explain with reasons.

12. Why are birds called glorified reptiles?

13. Why do sponges belong to the phylum Porifera?

14. Why Mustard is a dicotyledonous plant?

Life Cycle of a Bee

1. Define apiology and apiculture.

2. What is beekeeping?

3. What would happen to a honey bee colony if there were no queens?

4. Write five points to show the economic importance of beekeeping.

5. Explain the life cycle of a honeybee with necessary diagrams in brief.

6. How does a male bee develop from an unfertilized egg?

7. What purpose is served by keeping bee hives near crop fields?


1. Describe the three steps of cell division in short

2. What is cell division? What are the different types of cell division? Elucidate.

3. Describe nucleic acid and their types.

4. How is a son or a daughter determined? Explain with illustration.

5. Why is DNA a genetic agent?

6. Meiosis cell division causes variation in offspring why?

7. Define genes and nucleotides.

8. Introduce homogametic organisms.

9. What is a chromosome? Write a brief about the structure of a chromosome/

10. What is a chromosome made up of? Write the number of chromosomes in the diploid cells of the following organisms.

11. The diagram shows a type of acid found inside cells. Answer the following questions based on it.

12. Why are Honeybees called social insects?

13. Why honeybees are important pollinators.

14. What purpose is served by keeping bee hives near crop fields?

  1. Name the bases found in it.
  2. What are the components of the ribbon-like structures wrapped one over the other?
  3. How is the structure related to genetic activities? Explain in short.
  4. How does nucleic acid differ from the other types of nucleic acid found in cells? Mention any two points.

15. What is heredity and what defines genetics?

16. Define artificial insemination.

17. Define in vitro fertilization.

18. Why did Mendel select pea plants for his experiment? What character of pea plants were selected by Mendel for his experiment?

19. Describe cross-breeding and selective breeding in short.

20. Describe the law of dominance in short with a chart.

21. In what ratio will red-flowered and white-flowered pea plants be seen when red (RR) and white (rr) flowered pea plants are crossed together? Show with the help of a chart up to F2 generation.

22.  Why is genetic engineering a boon of science and technology for human beings?

23. Study the given diagram to answer the following questions.        





  1. Which filial generation is shown in the given diagram?
  2. How does it support the law of purity of gametes?
  3. Write the phenotype and genotype of the generation.
  4.  Mention the character of the parents who participated in it.

Physiological structure and life process

  1. Define the blood circulatory system.
  2. List the various components of blood.
  3. What is a heart attack?
  4. What is done in open heart surgery?
  5. What is a normal heartbeat rate?
  6. What is blood typing?
  7. Describe pulmonary and systemic circulation.
  8. Mention the different functions of blood.
  9. Write the function of different types of valves found in the heart.
  10. How can we prevent a heart attack?
  11. What is plasma and why is it important?
  12. Why is the blood red in color?
  13. Why are there no valves in the arteries?
  14. Why does an increased level of cholesterol trigger a heart attack?
  15. Why Arteries are deep-seated but veins superficial in our body?
  16. The table shows recipients and donors of different blood groups. Answer the following questions on the basis of it.

  1. Name the antigens and antibodies found in blood group B+.
  2. Which blood group of them has no antibodies?
  3. Why can blood group O- be transfused to any blood group?
  4. Why can the blood group AB+ be transfused to the person with AB+ only?

Nature and Environment

  1. Define global warming.
  2. What is climate change and what defines adaptation to climate change?
  3. Name a GHG.
  4. Name an endangered animal of the Himalayan region.
  5. Describe the national and international efforts made for adaptation and mitigation of climate change in short.
  6. Describe the effect of climate change in short.
  7. What role can we play in the mitigation of climate change?
  8. Mention any five endangered animals conserved in Nepal.
  9. Why does Global warming occur naturally as well?
  10. Mention any five endangered animals of the hilly and Himalayan region with the causes of risk of extinction.
  11. Why is Yarsagumba a summer grass winter worm?

Force and motion 

  1. State Newton’s law of gravitation.
  2. Define G. Also write its value and SI unit.
  3. What is the value of the universal gravitational constant (G)?
  4. Write two differences between freefall and weightlessness.
  5. Explain the feather and coin experiment.
  6. A person can lift a mass of 100 kg on the surface of the earth. What mass can he/she lift on the surface of the moon?
  7. In a hydraulic machine, the ratio of the cross-sectional area of the big cylinder to the small cylinder is 30:1. Calculate the load overcome by the big piston when applying the effort of 600N on the small piston.
  8. What will be the effect on the acceleration due to the gravity of the earth if it is compressed to the size of the moon?
  9. A coin and a feather are dropped in a vacuum. Which one will reach the ground first? Why?
  10. What is free fall? What happens to the weight of a body when it is falling freely under the action of gravity?
  11. A sphere of mass 40 kg is attracted by another sphere of mass 15 kg with a force of 9.8x10⁻⁷ N. Find the value of the universal gravitational constant if the centers of spheres are 20 cm apart.
  12. Calculate the force of attraction between two bodies with a mass of 100 kg each and they are 1 m apart on the surface of the earth. Will the force of attraction be different if the same bodies are taken on the moon, their separation remaining constant?


  1. State Pascal’s law.
  2. Mention two factors that affect pressure due to liquid contained in a vessel.
  3. Write any one difference between the law of floatation.
  4. Mention a factor that can affect upthrust.
  5. What is the role of density in the floatation of bodies?
  6. Mention the factors that affect the upthrust applied on a body.
  7. State Pascal’s law. Name any two instruments based on Pascal's law.
  8. Describe the experimental verification of Archimedes' principle.
  9. How does a hydraulic garage lift function? Explain with an illustration.
  10. Why does Ice float on water?
  11. The size of an air bubble increases when it comes up and up in water why?
  12. Why do deep-sea divers wear diving suits?
  13. The weight of a piece of stone, when fully immersed in water, is 18N and it displaced 4N of water. What is the weight of the stone in the air?
  14. A 15cm long cube made of oak floats in water with 10.5cm of its depth below the surface and with its sides vertical. What is the density of the cube? [ density of water= 100 Kg $M^3$.


  1. Define heat and specific heat capacity.
  2. What is one calorie heat?
  3. What is an anomalous expansion of water?
  4. What is the relation of heat with its factors?
  5. Describe the structure of a digital thermometer with a diagram.
  6. Explain the structure of a clinical thermometer.
  7. Explain the advantage of the more specific heat capacity of water in short.
  8. What are the similarities and dissimilarities between heat and temperature?
  9.  Why is Mercury heated faster than water?
  10. Why is the thermometer bulb made of a thin wall but the stem is thick-walled?
  11. When a beaker filled with water at $4^o$C is cooled or heated, the water overflows from the beaker why?
  12. If the specific heat capacity is 380 $JKg^{-1}$ $^0C^{-1}$, what is the thermal capacity of 5 kg of copper?
  13. A pressure cooker of mass 2 Kg at a temperature of $25^o$C requires 2.1 × $10^5$J heat energy to increase its temperature to $50^o$C.
  14. The temperature of 600g of a certain metal is $100^o$c. It is then placed in 300g of water at $15^o$C. If the final temperature is $20^o$C, calculate the specific heat capacity of the metal.
  15. The temperature of the water is 50C in the winter season. If 20 liter of water has to be heated to $35^o$ C for taking a bath, calculate the amount of heat required for it.( specific heat capacity of water if 4200J$Kg^{-1}$ $^0C^{-1}$, mass of 1 litre of water = 1Kg)


  1. Explain the dispersion of light in a prism in brief with a labeled diagram.
  2. Mention the condition required for the total internal reflection.
  3. Do sound waves show the properties of light waves? Justify your answer by giving examples.
  4. State the laws of refraction of light.
  5. Define dispersion of light.
  6. What is the relation between the refractive index and the speed of light in a medium?
  7. Enlist any four events that are caused by the refraction of light.
  8. Describe in short the use of optic fibers in the information and communication sector.
  9. A ray of light is incident in air on the surface of a glass block. The angle of incidence is 300; calculate the angle of refraction. (R.I. of glass w.r.t. Air = 1.5)
  10. The refractive index of glass is 1.5 and the speed of light in a vacuum is 3 ×108 m/s. Find the speed of light in the glass.
  11. With what angles should a ray strike the surface of water to make an angle of refraction of 200 in water? The refractive index of water is 1.33.
  12. What is myopia?
  13. Which lens is used to correct hypermetropia?
  14. Define spectrum.
  15. What is the ray found above the red color in the spectrum?
  16. What are myopia and hypermetropia? How is it corrected?
  17. Write the formula for the power of the lens and magnification of the lens each.
  18. Sheetal wears a lens of power +2D. Answer the following questions.
  1. What is the defect of Sheetal’s version called?
  2. How is it corrected by using a lens? Show with the help of a suitable diagram.
  3. What causes this type of defect?
  4. How does she manage a newspaper while reading without using the lens? Why?

19. Why a person with hypermetropia cannot see the closest object?

20. What is the defect of vision in the eye shown in the given figure? What is to be done to correct this defect of vision? Explain.

21. Nabin uses the spectacles of power +1D. Calculate the focal length of the lens. What type of defect is he suffering from?

Electricity and Magnetism

  1. Who founded the law of electromagnetic induction?
  2. State the right hand’s thumb rule.
  3. State the right hand’s grip rule.
  4. Which instrument can convert kinetic energy into electrical energy?
  5. Write down the type of transformer in which the turning of wire in the secondary coil is less than that in the primary coil.
  6. Which type of transformer is used at power stations?
  7. State Faraday’s law of electromagnetic induction.
  8. Clarify Maxwell’s right-hand grip rule. For what purpose do we use this rule?
  9. Write the working method of a transformer.
  10. Describe thermal power plants in short. Also, analyze their merits and demerits.
  11. Write a short note on the importance of electric motors in modern life.
  12. Why are step-up transformers used in power stations?
  13. Why is hydroelectricity green energy?
  14. Why is the core of a transformer laminated with varnish?
  15. A transformer has 220V primary voltage and 1000 turns of the primary coil. How many turns of the secondary coil will be needed to produce 110 volts from that transformer?
  16. A transformer has 200 primary turns and 150 secondary turns. If the operating voltage for the load connected to the secondary is measured to be 300V, what is the voltage supplied to the primary coil?
  17. Study the diagram and calculate the secondary voltage in it. 

18. Study the diagram and answer the following questions.

  1. What type of transformer is shown in the diagram?
  2. Label A, B, C, and D in the diagram.
  3.  For what purpose is the transformer used?
  4. Mention any two applications of it.
  5. What is the cause of laminating A?

The Universe  

  1. Define redshift.
  2. What is the future of the universe if the triangle on the surface has an angle whose sum is 1800?
  3. Define singularity.
  4. Mention the role of gravity during nuclear fusion in stars.
  5. Define the critical density of the universe.
  6. Describe the importance of gravitational force in the universe in short.
  7. How can we say that the universe is changing continuously?
  8. What is the finding of Hubble’s study about the motion of the heavenly bodies?
  9. What is the theory of relativity founded by Albert Einstein?
  10. Why do the galaxies and black holes adjust at a point in the future?
  11. Why is gravitation the ultimate force of the universe?

Information and Communication Technology

  1. What is a digital signal? Name any two devices that use digital signals in our daily lives.
  2. Why are geostationary satellites launched in the parking orbit?
  3. What is online reputation?
  4. Explain the process of converting digital data into a digital signal by line coding.
  5. What is digital well-being? How do the internet and the virtual world affect the physical, social, and emotional health of netizens?
  6. Define audio-visual materials. Write down any five characteristics of audio-visual materials and explain any two of them.
  7. Write down the meaning of a netizen. Mention any three responsibilities of good netizens.

Classification of elements

  1. What is the periodic table?
  2. Introduce Mendeleev’s periodic law and the Modern periodic table.
  3. What are isotopes, groups, and periods?
  4. What factors do the valencies of elements depend upon?
  5. What is the basic difference between Mendeleev’s periodic law and the modern periodic law?
  6. In which group, period, and block will the element with atomic number 20 be present?
  7. What are the major differences between metals and nonmetals?
  8. The increasing order of reactivity among group 1 elements is Li < Na < K . Explain.
  9. What are the features of the modern periodic table?
  10. Why are Li, Na, and K placed in the same group of the periodic table?
  11. Write the general outer electronic configuration of S-,p–, d-, and f- block elements.
  12. Why is sodium less reactive than potassium?
  13. Why are the members of group IA called alkali metals?
  14. Why do transition elements have variable valency?
  15.  Study the given electronic configuration of the elements and answer the following questions:

a. 2,8,1       b. 2,8      c. 2,8,7    d.1

  1. Give the names of a metal and a non-metal from above.
  2. Which one of the above elements is inert and why?
  3.  Identify those elements which are placed in Group 17 and Group 1.

Chemical Reaction

  1. What are the parts of the chemical equation?
  2. Name the chemical reaction in which two substances exchange ions.
  3. What is the difference between a reactant and a product?
  4. How does pressure affect the rate of gaseous reactions?
  5. Define acid-base reaction with an example.
  6. What is a chemical reaction? What are the conditions required for a chemical reaction? Explain any three with an example.
  7. Explain addition recitation and single displacement reaction with an example.
  8. What is a catalyst? How does a catalyst affect the rate of recitation?
  9. Describe an activity to demonstrate that the rate of chemical reaction increases with the increase of temperature.
  10. Two chemical substances, when mixed at room temperature, react, slowly suggesting two ways of increasing the rate of this reaction.
  11. Why is silver bromide stored in dark bottles in the laboratories?
  12. Why is the rate of chemical reaction important in real life?
  13. Identify each type of reaction;
  1. $2NH_4NO_3$ $\rightarrow$ $2N_2+4H_2O+)_2$
  2. 2Hg+$O_2$ $\rightarrow$ 2HgO
  3. KOH+HCI $\rightarrow$ KCI+$H_2$O

14. Change the following word equation into a chemical equation and then balance them.

  1. Lead oxide + Carbon  →  Carbon monoxide + Lead
  2. Potassium chlorate   → Potassium chloride + Oxygen
  3. Aluminium + Chlorine  →  Aluminium chloride


  1. What are the uses of carbon dioxide?
  2. What are the physical properties of ammonia?
  3. How does the atmosphere act as a blanket?
  4. Ammonia turns red litmus into blue. What does it show?
  5. What is meant by dry ice? What is it used for?
  6. How is carbon dioxide collected in the laboratory?
  7. Describe the threat to the beauty of the historical monuments of Nepal due to the acid rain.
  8. Write any two advantages of the greenhouse effect in the atmosphere and two disadvantages of the greenhouse effect.
  9. If a worker is going to enter into a well for cleaning purposes what suggestions will you give to him to pretest that the well is safe to enter or not?
  10. Why does carbon dioxide not support burning but Mg burns in it?
  11. Why is Carbon dioxide gas collected in an open gas jar?
  12. What would happen if greenhouse gases were not present in the atmosphere of the earth?
  13. Study the given figure and answer the following questions.

  1.  Which gas is collected in the gas jar?
  2. Write the balanced chemical equation involved in the process.
  3.  Name the compound formed in the gas jar if the jar is moist.
  4. Write any three uses of this gas.


  1. Define minerals.
  2. What is an ore?
  3. What is calcination of ores ?
  4. Which metal is extracted from magnetite and argentite?
  5. Name some important methods of concentrating ores.
  6. Define Roasting and Calcination.
  7. How is the method of extracting the metals high up in the reactivity series different from the method of extracting other metals?
  8. Write the principles of the fourth floatation process and electromagnetic separation.
  9. Briefly describe the methods by which concentrated ore is converted into metallic oxides for the extraction of metals.
  10. Write a note on roasting and calcination with suitable diagrams.
  11. Why is gold found in the free state?
  12. Why Iron and aluminium do not freely occur in nature?

Hydrocarbons and Their compounds

  1. Define a saturated hydrocarbon.
  2. Write any three uses of methane and alcohol.
  3. What does IUPAC stand for?
  4. State a common use of butane.
  5. “Acetylene is an unsaturated hydrocarbon.” Justify the statement with its molecular structure.
  6. How are hydrocarbons important in our daily life? Describe.
  7.  Why is glycerol considered as alcohol? Also, mention its uses in our daily life.
  8. Compare alkane, alkene, and alkyne in three points.
  9. Why are alkenes called olefins?
  10. Why is propane a saturated hydrocarbon?
  11. The structural formula of hydrocarbons is given. Answer the following questions.

  1. Which compound is formed if all ‘OH’ groups are replaced by ‘H’?
  2. Give a use of the compound formed in this way.

12. Sketch molecular structure of : 

  1. Trihydric alcohol
  2. Ethylene glycerol
  3. Ethyl alcohol
  4.  Iso-butane

Material Used in Daily Life

  1. Define industrial chemistry.
  2. What is the negative effect of sodium benzoate preservative?
  3. Disposable ceramic is a chemical pollutant. Justify.
  4. Name any two natural preservatives.
  5. What is waste management?
  6. What are the problems with food preservatives?
  7. Define pesticides. What are the effects of excessive use of pesticides?
  8. Write the full form of; DDT, BHC, BHT, and BHA.
  9. Define non-biodegradable waste. Explain it with an example.
  10. What will happen if chemical wastes are not properly managed?
  11. Can we preserve food safely at home? Explain with some examples.
  12. In what way is the use of natural preservatives better than the use of man-made chemical preservatives?
  13. How is soap manufactured? explain.
  14. Why are chemical fertilisers the chemical pollutants?
  15. Why detergents are non-biodegradable while soap nuts are biodegradable.
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