Question 1

Question 1Identify the product which represents the solid state in the below reaction.Barium chlorideBarium sulphateSodium chlorideSodium sulphate

Accepted Answer

Barium sulphateReason — When sodium sulphate is reacted with barium chloride, a white ppt. of barium sulphate is produced.Na2SO4 (aq) + BaCl2 (aq) ⟶ BaSO4 (s) + 2NaCl (aq)

Question 2

Question 2The colour of the solution observed after 30 minutes of placing zinc metal to copper sulphate solution isBlueColourlessDirty greenReddish Brown

Accepted Answer

ColourlessReason — Zinc due to its high reactivity displaces copper from copper sulphate and forms zinc sulphate and thus copper gets deposited and the blue coloured solution becomes colourless.Zn + CuSO4 ⟶ Cu + ZnSO4

Question 3

Question 3Mild non-corrosive basic salt isCa(OH)2NaClNaOHNaHCO3

Accepted Answer

NaHCO3Reason — Sodium hydrogen carbonate [NaHCO3] is a mild non-corrosive basic salt.

Question 4

Question 4On adding dilute sulphuric acid to a test tube containing a metal 'X', a colourless gas is produced when a burning match stick is brought near it. Which of the following correctly represents metal 'X'?SodiumSulphurCopperSilver

Accepted Answer

SodiumReason — When sodium is reacted with dil. H2SO4, sodium sulphate is formed and hydrogen gas is liberated.2Na + H2SO4 (dil.) ⟶ Na2SO4 + H2

Question 5

Question 5Which one of the following correctly represents Sodium oxide?

Accepted Answer

Reason — The valency of sodium is 1 and that of oxygen is -2. Two sodium cations and one oxygen anion form an ionic bond and the chemical formula of sodium oxide is Na2O.

Question 6

Question 6An element with atomic number ............... will form a basic oxide.7 (2,5)17 (2,8,7)14 (2,8,4)11 (2,8,1)

Accepted Answer

11 (2,8,1)Reason — Metals form basic oxides with 1 to 3 electrons in their outermost shell, whereas non-metals form acidic oxides with 4 to 8 electrons in their outermost shell.

Question 7

Question 7An element 'M' has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of 'M' is:10121418

Accepted Answer

14Reason — Electrons are in third shell, so, first and second shells must be completely filled i.e., they have 2 and 8 electrons. Now, as third shell has half of second shell, so, there will be 4 electrons in the third shell.Hence, 'M' will have 2+8+4 = 14 electrons.

Question 8

Question 8Generally food is broken and absorbed within the body of organisms. In which of the following organisms is it done outside the body?AmoebaMushroomParamoeciumLice

Accepted Answer

MushroomReason — Mushroom as well as all other Fungi show extracellular digestion. Their cell wall release enzymes which digest the food outside their body and the digested food is then absorbed.

Question 9

Question 9Receptors are usually located in sense organs. Gustatory receptors are present intonguenoseeyeear

Accepted Answer

tongueReason — Gustatory receptors are present in taste buds of tongue. They perceive taste of food.

Question 10

Question 10A farmer wants to grow banana plants genetically similar enough to the plants already available in his field. Which one of the following methods would you suggest for this purpose?RegenerationBuddingVegetative propagationSexual reproduction

Accepted Answer

Vegetative propagationReason — Banana is reproduced by vegetative method (rhizomes). Resulting plants are identical to mother plant.

Question 11

Question 11Height of a plant is regulated by:DNA which is directly influenced by growth hormone.Genes which regulate the proteins directly.Growth hormones under the influence of the enzymes coded by a gene.Growth hormones directly under the influence of a gene.

Accepted Answer

Growth hormones under the influence of the enzymes coded by a gene.Reason — Genes code for enzymes that influence the synthesis and regulation of growth hormones, ultimately determining the plant's overall growth and height.

Question 12

Question 12A sportsman, after a long break of his routine exercise, suffered muscular cramps during a heavy exercise session. This happened due to:lack of carbon dioxide and formation of pyruvate.presence of oxygen and formation of ethanol.lack of oxygen and formation of lactic acid.lack of oxygen and formation of carbon dioxide.

Accepted Answer

lack of oxygen and formation of lactic acid.Reason — Muscular cramps during heavy exercise are often associated with the accumulation of lactic acid in muscles. This occurs when there is insufficient oxygen available to meet the energy demands of the muscles, leading to anaerobic metabolism and the production of lactic acid.

Question 13

Question 13An object is placed in front of a convex mirror. Its image is formed :at a distance equal to the object distance in front of the mirror.at twice the distance of the object in front of the mirror.half the distance of the object in front of the mirror.behind the mirror and it's position varies according to the object distance.

Accepted Answer

behind the mirror and it's position varies according to the object distance.Reason — When an object is placed in front of a convex mirror, its image is formed behind the mirror and it's position varies according to the object distance.

Question 14

Question 14When light enters the atmosphere it strikes on extremely fine particles, which deflect the rays of light in all possible directions, This is due to -reflection of lightatmospheric refractionscattering of lightdispersion of light

Accepted Answer

scattering of lightReason — When light enters the atmosphere it strikes on extremely fine particles, which deflect the rays of light in all possible directions, This is due to scattering of light.

Question 15

Question 15In 1987, an agreement was formulated by the United Nations Environment Programme (UNEP) to freeze the production of “X” to prevent depletion of “Y”. “X” and “Y” respectively referred here are:Ozone; CFCsCFCs; rays UVCFCs; OzoneUV rays; Diatomic oxygen

Accepted Answer

CFCs, OzoneReason — In 1987, an agreement was formulated by the United Nations Environment Programme (UNEP) to freeze the production of CFCs to prevent the depletion of Ozone.

Question 16

Question 16Which of the following features relates to biodegradable substances?Broken down by biological processesRemain inertPersist in environment for long timeMay harm the ecosystem

Accepted Answer

Broken down by biological processesReason — Biodegradable substances are the substance that degrade or decompose naturally by the action of microorganisms.

Question 17

Question 17Assertion: Rusting of Iron is endothermic in nature.Reason: As the reaction is slow, the release of heat is barely evident.Both A and R are true, and R is the correct explanation of A.Both A and R are true, and R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is false but R is trueReason — Rusting of iron is an exothermic process. It is a slow process and the amount of heat released isn't significant per unit of time.

Question 18

Question 18Assertion: Probability of survival of an organism produced through sexual reproduction is more than that of organism produced through asexual mode.Reason: Variations provide advantages to individuals for survival.Both A and R are true, and R is the correct explanation of A.Both A and R are true, and R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true, and R is the correct explanation of A.Reason — Variations help individual to adapt to the changes in the environment and hence increases the chance of survival.

Question 19

Question 19Assertion : A compass needle is placed near a current carrying wire. The deflection of the compass needle decreases when the magnitude of the current in the wire is increased.Reason : The strength of a magnetic field at a point near the conductor increases on increasing the current.Both A and R are true, and R is the correct explanation of A.Both A and R are true, and R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is false but R is true.Reason — A compass needle is placed near a current carrying wire. The deflection of the compass needle increases when the magnitude of the current in the wire is increased because strength of a magnetic field at a point near the conductor increases on increasing the current.

Question 20

Question 20Assertion: Biodegradable substances result in the formation of compost and natural replenishment.Reason: It is due to breakdown of complex inorganic substances into simple organic substances.Both A and R are true, and R is the correct explanation of A.Both A and R are true, and R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is true but R is false.Reason — Biodegradable substances result in the formation of compost and natural replenishment due to breakdown of complex organic substances into simple organic substances.

Solved 2024 Sample Question Paper CBSE Class 10 Science

Section A (Objective Type Questions 1 Mark Each)

Section B (Very Short Answer Questions 2 Marks Each)

Section C (Short Answer Questions 3 Marks Each)

Section D (Long Answer Questions 5 Marks Each)

Section E (Source/Case Based Questions 4 Marks Each)