CBSE Class 10 Science Compartment Question Paper 2023 with Answer Key pdf (Set 1- 31/C/1) is available for download here. The exam was conducted by Central Board of Secondary Education on July 20, 2023 in the Morning Session 10:30 AM to 1:30 PM. The question paper comprised a total of 39 questions divided among 5 sections.
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CBSE Class 10 2023 Science 31-C-1 Compartment Question Paper with Solution PDF
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Question 1:
In the electrolysis of water, if the mass of the gas collected at the anode is \(m_a\) and the mass of the gas collected at the cathode is \(m_c\), the value of \(\frac{m_c}{m_a}\) is :
Consider the following substances :
(i) Acidified K\(_2\)Cr\(_2\)O\(_7\)
(ii) Alkaline KMnO\(_4\)
(iii) Oxygen
(iv) Hydrogen
Out of these, the commonly used oxidising agents are :
Select from the following compounds which is not a base :
2 g of yellow sulphur powder is burnt in a china dish and the fumes are collected in a test tube. Water is added in the test tube and the solution is tested separately with blue and red litmus paper. The correct option is :
Which one of the following metals is malleable and a poor conductor of electricity ?
Which one of the following molecules is produced initially when glucose breaks down in the cytoplasm of a cell in aerobic as well as anaerobic respiration ?
As compared to daytime, the amount of carbon dioxide released by the plants during night is more because :
The organism in which an outgrowth on the parent body develops into a new individual is :
In a cross between pure tall pea plants (TT) and pure dwarf pea plants (tt) the offsprings of F\(_1\) generation were all tall. When F\(_1\) generation was self-crossed, the gene combinations of the offsprings of F\(_2\) generation will be :
When a narrow beam of white light passes through a glass prism it splits into its component colours. This phenomenon is called :
A material used for making heating elements of electrical heating devices should have :
The resistance of a wire does not depend on its :
The shape of magnetic field lines produced (i) inside a solenoid (ii) around a straight conductor, both carrying current of the same magnitude are, respectively :
Assertion (A) : In the reaction, Na\(_2\)SO\(_4\) + BaCl\(_2\) \(\longrightarrow\) BaSO\(_4\) + 2NaCl, sodium chloride is precipitated.
Reason (R) : When an aqueous solution is added to another aqueous solution, an insoluble substance is formed, which is called precipitate.
Assertion (A) : A hormone called abscisic acid inhibits growth in plants.
Reason (R) : The role of auxins is opposite to that of abscisic acid in plants.
Assertion (A) : Each human trait is influenced by both paternal and maternal DNA.
Reason (R) : As compared to the father, the mother contributes more amount of genetic material to the child.
Assertion (A) : A rainbow is an artificial spectrum of white light appearing in the sky after a rain shower.
Reason (R) : The water droplets act like small prisms.
(a) A metal ‘A’ reacts violently with cold water and the gas evolved catches fire. Another metal ‘B’ when dipped in water starts floating. The metal ‘C’ does not react either with cold or hot water, but reacts with steam. The metal ‘D’ does not react with water at all. Identify the metals ‘A’, ‘B’, ‘C’ and ‘D’.
(i) Name the colour imparted by (1) sodium chloride and (2) calcium chloride.
(ii) Are these compounds soluble in organic solvents such as kerosene or petrol? Justify your answer.
Name the glands which add their secretions to the sperms. List two functions of these secretions.
“In human beings, the sex of a newborn child depends on the father and not the mother.” Justify this statement with the help of a flow diagram.
(a) Find the magnification of the image formed by a spherical mirror from the following data :
\(u = -20\) cm,\; \(f = -15\) cm.
(b) Draw a labelled ray diagram for the image formation by a concave mirror when an object is placed between its centre of curvature and focus.
What will happen if an electric oven of rating 3 kW; 220 V is operated in a domestic electric circuit (220 V) that has a current rating of 10 A? Give reason to justify your answer.
(a) State any one advantage of using cloth bags over plastic bags.
(b) List any two methods by which the solid wastes generated in urban areas can be safely disposed off.
What is photosynthesis? Name the organelle and the organs in which photosynthesis takes place. Where does the oxygen liberated come from during this process? What happens to the carbohydrates which are not immediately used by the plant?
(a) An organic compound ‘X’ when reacts with sodium liberates hydrogen. The same compound ‘X’ when heated at 443 K in the presence of concentrated sulphuric acid gives an unsaturated hydrocarbon.
(i) Identify ‘X’.
(ii) Write the chemical equations for the above mentioned reactions and state the role of concentrated sulphuric acid in the second reaction.
(b) (i) Why are carbon compounds exceptionally stable?
(ii) Differentiate between saturated and unsaturated compounds. Give structures of both the types of compounds having three carbon atoms in their molecules.
View Solution
Difference:
Saturated compounds contain only single bonds between carbon atoms (C–C).
Unsaturated compounds contain at least one double or triple bond (C=C or C≡C) between carbon atoms.
Examples with three carbon atoms:
Saturated compound (Propane): \[ CH_3 - CH_2 - CH_3 \]
Unsaturated compound (Propene): \[ CH_2 = CH - CH_3 \]
Therefore, propane is a saturated hydrocarbon (alkane) and propene is an unsaturated hydrocarbon (alkene).
Quick Tip: Saturated: only single bonds (alkanes); Unsaturated: double/triple bonds (alkenes/alkynes).
(a) Give the structure and function of alveoli in human respiratory system.
(b) What is meant by residual volume of air in the lungs?
Write any two ways by which plants obtain carbon dioxide. What causes the opening and closing of the stomata?
What is Tyndall effect? Give two examples where this phenomenon is observed. Give reason to explain this phenomenon.
With the help of a labelled circuit diagram, illustrate the pattern of the magnetic field lines of the magnetic field produced around a straight current carrying conductor. Explain how, with the help of right-hand thumb rule, we can determine and mark the direction of magnetic field lines due to a current.
Define trophic levels. At which trophic level do we find (i) secondary and (ii) tertiary consumers in a food chain? What will happen if all the organisms of a trophic level die? Give reasons to justify your answer.
Question 34:
Define water of crystallisation.
View Solution
Water of crystallisation is the fixed number of water molecules present in a crystalline compound. These water molecules are chemically combined with the substance and give it a definite crystalline structure and colour.
Quick Tip: Water of crystallisation makes hydrated salts appear coloured.
(a) Name the parts in the human female reproductive system where the following functions take place:
(1) Maturation of eggs
(2) Fusion of the egg and the sperm
(3) Implantation of the zygote
(b) Explain by giving one example each:
(1) Unisexual flowers
(2) Bisexual flowers
The commercial unit of electric energy is commonly known as ‘unit’. Write its actual name and establish the relationship between this unit and the SI unit of energy.
(a) Where is iron placed in the reactivity series of metals? Write the form/forms in which its ores are found in nature.
(b) Why is aluminium used to join railway tracks or the cracked machine parts of ‘iron’? Write a balanced chemical equation for the reaction which occurs.
(a) How is the brain protected from shocks and injuries?
(b) Write the main functions of (i) sensory neuron and (ii) motor neuron in a reflex arc.
(c) Which part of the brain is involved in activities like (i) picking a pencil and (ii) vomiting? State whether these actions are voluntary or involuntary.
OR (c) How does the central nervous system communicate with other parts of the body to carry out various activities? Name two components of this system.
(a) Define the term absolute refractive index of a medium.
(b) Absolute refractive indices of water and glass are \(\frac{4}{3}\) and \(\frac{3}{2}\) respectively.
(i) In which one of the two media is the speed of light more?
(ii) If a ray of light enters obliquely from glass to water, will it bend towards the normal or away from the normal?
(c) The absolute refractive indices of water and glass are \(\frac{4}{3}\) and \(\frac{3}{2}\) respectively. If the speed of light in glass is \(2 \times 10^8\) m/s, find the speed of light in (i) water and (ii) vacuum.
OR (c) “A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw a labelled ray diagram to justify this statement.
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