CBSE Sample Papers for Class 10 Science Paper 10
These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 10.
Time Allowed: 3 hours
Max. Marks: 80
- The question paper comprises two sections, A and B. You are to attempt both the sections.
- All questions are compulsory.
- All questions of Section-A and B are to be attempted separately.
- There is an internal choice in three questions of three marks each, two questions of five marks each and one question
- (for assessing the practical skills) of two marks.
- Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
- Question numbers 3 to 5 in Section- A are two marks questions. These are to be answered in 30 words each.
- Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
- Question numbers 16 to 21 in Section-d are five marks questions. These are to be answered in 70 words each.
- Question numbers 22 to 27 in Section- B are based on practical skills. Each question is a two marks question. These are to be answered in brief.
Tooth enamel is one of the hardest substance in our body. How does it undergo damage due to eating chocolates and sweets? What should we do to prevent it?
Name the process of converting vegetable oil to vegetable ghee.
A person is not able to see distinctly the objects placed beyond 90 cm from him. Give reason to identify the defect in his eye. Determine the nature of lens used to correct the defect.
List two natural ecosystems.
Why are environmentalists insisting upon ‘sustainable natural resource management ? Give any three reasons.
A brown substance ‘X’ on heating in air forms a substance ‘Y’. When hydrogen gas is passed over heated ‘Y’, it again changes back into ‘X’.
- Name the substance ‘X’ and ‘Y’.
- Name the type of chemical reactions occurring during both the changes.
- Write the chemical equations of the reactions.
State reason for the following:
- Lemon is used for restoring the shine of tarnished copper vessels.
- A metal sulphide is converted into its oxide to extract the metal from its sulphide ore.
- Copper wires are used in electrical connections.
Two carbon compounds A and B have the molecular formula C3H8 and C3H6 respectively. Which one of the two is most likely to show addition reaction? Justify your answer. Explain with the help of a chemical equation, how an addition reaction is useful in vegetable ghee industry.
What is meant by isomers? “We cannot have isomers of the first three members of alkane series”. Give reason to justify this statement. Draw the structures of two isomers of pentane, C5H12.
Nervous and hormonal system together perform the function of control and coordination in human beings. Justify the statement.
Define ‘hormones’. Name the hormone secreted by thyroid. Write its function. Why is the use of iodised salt advised to us?
“Different species use different strategies to determine sex of a newborn individual. It can be environmental cues or genetically determined’. Explain the statement by giving example for each strategy.
What is speciation? List four factors responsible for speciation.
A student finds the writing on the blackboard as blurred and unclear when sitting on the last desk in the classroom. He however, sees it clearly when sitting on the front desk at an approximate distance of 2m from the blackboard. Draw ray diagrams to illustrate the formation of image of the blackboard writing by his eye-lens when he is seated at the
- last desk
- front desk.
Name the kind of lens that would help him to see clearly even when he is seated at the last desk. Draw a ray diagram to illustrate how this lens helps him to see clearly.
State the cause of dispersion of white light passing through a glass prism. How did Newton show that white light of sun contains seven colours using two identical glass prisms. Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the focus of the first prism.
Name the eye defect in which eye lens becomes cloudy or milky. Mention the method for its correction. A person uses a lens of power -1.0 D for correcting his distant vision and for correcting his near vision he uses a lens of power +2.0 D. Calculate the focal length of the lenses required to correct these defects. Explain why a normal eye is not able to see clearly the object placed closer than near point.
A coil of insulated copper wire is connected to a galvanometer. What will
happen if a bar magnet is
- pushed into the coil
- withdrawn from inside the coil
- held stationary inside the coil?
Mr. Kumar visited the newly built bungalow of his friend Mr. Kamat. There he observed that a big solar geyser was installed on the roof. Mr. Kumar told his friend that he was unable to understand why he was miser in spending money on installation of electric geysers in each bathroom. Mr. Kamat not only explained him the reason rather convinced Mr. Kumar too to install solar geyser in his house.
- Explain the values exhibited by Mr. Kamat.
- List the advantages of solar geyser that convinced Mr. Kumar to adopt it.
- If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?
- List in tabular form two differences between an acid and a base based on their chemical properties.
- Write the names given to the vertical columns and horizontal rows in the Modern Periodic Table. How does the metallic character of elements vary on moving down a vertical column? Give reason in support of your answer.
- An element P (atomic number 20) reacts with an element Q (atomic number 17) to form a compound. Answer the following questions giving reason: Write the position of P and Q in the Modern Periodic Table and the molecular formula of the compound formed when P reacts with Q.
- Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
- If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.
- What happens when:
- Accidently, Planaria gets cut into many pieces ?
- Bryophyllum leaf falls on the wet soil ?
- On maturation sporangia of Rhizopus bursts ?
- State the basic requirement for sexual reproduction? Write the importance of such reproduction in nature.
- Draw a longitudinal section of a flower and label the following parts:
- Part that develops into a fruit
- Part that produces pollen grain
- Part that transfers male gametes
- Part that is sticky to trap
- Name the parts labeled A, B, C, D in the diagram given below:
- Rohit claims to have obtained an image twice the size of object with a concave lens. Is he correct? Give reason for your answer.
- Where should an object be placed in case of a convex lens to form an image of same size as of the object? Show with the help of ray diagram the position and the nature of the image formed.
- With the help of ray diagram, illustrate the change in position, nature and size of the image formed if the convex lens in case of (ii) is replaced by concave lens of same focal length.
- The voltage – current (V-I) graph for a conductor at two different temperature T1 and T2 is shown. At which of the two temperatures the resistance of the conductor is higher? Justify your answer.
- The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor
are given below:
Plot a graph between V and I and calculate the resistance of the resistor.
- How will you convert a given set of resistors so that the equivalent resistance is increased? Give reason for your answer.
In the above circuit diagram, calculate:
- the value of current through each resistor.
- the total current in the circuit.
- the total effective resistance of the circuit.
When we add water to quick lime we observe some changes. On the basis of those changes what can be concluded about the reaction between quick lime and water?
Iron filings were added to a solution of copper sulphate. After 10 minutes, it was observed that the blue colour of the solution changes and a layer gets deposited on iron filings. What is the colour of the solution and the layer deposited?
What type of seeds are used in the experiment to show that CO, is given out during respiration?
What is the function of cotyledons?
For determining focal length of a concave mirror, a teacher asks her students to identify concave mirror from a few mirrors lying on the table. The reason given by A, B, C and D for picking up the right mirror is as follows: A: the mirror is depressed at the center and self image formed is enlarged and erect. B: the mirror is raised at the center and self image formed is smaller and erect. C: the mirror is plane all over and self image is of same size. D: the mirror is depressed at the center and self image formed is enlarged and inverted. Which reason is correct? Justify your answer.
In an experiment to study the dependence of current on potential difference across a resistor, a student obtained the graph as shown in the diagram.
Find the value of resistance of the resistor?
The following apparatus is available in a laboratory.
- Cell : Adjustable from 0 to 1.5 volt
- Resistor : 4Ω and 12Ω
- Ammeters : A1 of range 0 to 3 A; Least count 0.1 A
A2 of range 0 to 1 A ; Least count 0.05 A
- Voltmeters : V1 of range 0 to 10 V; Least count 0.5 V
V2 of range 0 to 5 V; Least count 0.1 V
Find the best combination of ammeter and voltmeter for finding the equivalent resistance of the resistors.
The bacteria present in our mouth break down the sugar (due to eating chocolates and sweets) to form acid (lactic acid) which damages tooth enamel. We should brush our teeth with tooth paste which are bases regularly to prevent tooth decay.
Hydrogenation converts vegetable oil to vegetable ghee.
It is because the image of a distant object is formed in front of the retina and not at the retina itself.
- This defect is called Myopia (Near-sightedness)
- Concave lens is used to bring the image back on to the retina and thus the defect is corrected.
The two naturally occurring ecosystems are: Forest, Lake, Pond, River (Any two)
Environmentalists are insisting upon sustainable natural resource management because:
- The non-renewable resources are limited, so we should use them judiciously.
- Depletion of one resource may affect other resources also.
- This will prevent pollution and maintain ecological balance.
- We should preserve the existing environment for future generations.
(i) X— Cu; Y — CuO.
(ii) Oxidation and reduction reactions-take place during the changes respectively.
(iii) 2Cu + O2 , 2CuO (Oxidation)
CuO + H2 Cu + H2O (Reduction)
- Copper vessels tarnish by the formation of basic copper carbonate. Acid present in lemon neutralises the basic effect and restores the shine of copper vessels.
- This is because oxides can be easily reduced to metal.
- Copper wires are good conductor of electricity, so, they are used in electrical connections.
Compound A(C3H8) is saturated and compound B(C3H6) is unsaturated hydrocarbon. As we know that addition reactions are a characteristic property of unsaturated hydrocarbons, thus, the compound B(C3H6) is most likely to show addition reaction.
Vegetable oils are unsaturated compounds containing double bonds. They are in the liquid state. When a vegetable oil is heated with hydrogen in the presence of finely divided nickel catalyst, then a saturated fat called vegetable ghee is formed. This is a solid or (a semi-solid) at room temperature.
Isomers are those compounds which have same molecular formula and different structural formula. In first three members of alkane, branching is not possible, therefore isomers are not possible. Isomers of pentane are as follows:
Nervous and hormonal system together perform the function of control and coordination in human beings. Let us take an example, in the case of any emergency, stimulus is being perceived by CNS (central nervous system). The stimulus is analysed and the response is sent to the effectors. Simultaneously, sympathetic nerves stimulate adrenal gland to release adrenaline which regulates blood pressure, increases heartbeat, constricts blood vessels and dilates pupil, etc. So, both nervous and endocrine systems interact and overcome the crisis together.
Hormones are chemical substances found in living beings which performs the function of control and coordination of various physiological activities. The hormone secreted by thyroid gland is thyroxin. It regulates carbohydrate, fats and protein metabolism. Iodine is a constituent of thyroxin. Iodized salt provides sufficient iodine for thyroxin formation otherwise the deficiency of thyroxin develops a disorder called goitre.
Environmental cue: In some animals, the temperature at which fertilised eggs are kept determines whether the animal developing in egg is male or female. In some animals like snail, individual can change sex.
Genetical cue : In human a child who inherits an X chromosome from the father will be a girl and one who inherits a Y chromosome from the father will be a boy.
Speciation is the formation of new species from the pre-existing population. Factors responsible for speciation:
- Genetic drift
- Natural selection
- Geographical isolation
A person with myopia can see nearby objects clearly but cannot see distant objects distinctly. A person with this defect has the far point nearer than infinity. Such a person may see clearly upto a distance of a few metres. Concave lens would help him to see clearly when he is seated at the last desk.
Different colours of white light bend through different angles with respect to the incident ray as they pass through a prism. Violet light bends the most and red the least. Thus, each colour emerges along different paths and white light gets dispersed.
In Cataract lens becomes milky or cloudy.
This defect can be corrected through a cataract surgery.
Power = – ID =
ƒ = – 1m
ƒ = 0.5 m
This is because the normal eye has a power of accommodation which enables the objects as close as 25 cm.
- When a bar magnet is pushed into the coil, a momentary deflection is observed in the galvanometer. This deflection indicates that a momentary current is produced in the coil.
- When a bar magnet is withdrawn from the coil, the deflection of galvanometer is in opposite direction. It indicates that a current of an opposite direction is produced.
- When a bar magnet is held stationary inside the coil, there is no deflection in the galvanometer. It indicates that no current is produced in the coil.
- Mr. Kamat is a responsible person who knows that everyone should minimise the use of non-renewable source of energy. He is conscious of his duty to convince other’s also to make right choice for the cause of energy conservation.
- Solar geyser runs on solar energy which is renewable. It would save his electricity bill. Also, use of solar energy does not cause environment pollution anywhere.
- The hand is washed immediately with plenty of water and a paste of sodium hydrogencarbonate (a base) is applied to neutralise the acid.
Acids Bases 1. H+ ions are released in aqueous solution. 1. OH– ions are released in aqueous solution. 2. Reacts with metal carbonates to liberate CO2 gas.
2. No reaction takes place with metal carbonates.
- Vertical Columns are called Groups. Horizontal Rows are called Periods. On moving down a vertical column, metallic character of elements increases.
Reason : Ability to lose electrons increases on moving down the group due to increase in distance between the nucleus and the valence electrons. Also, there is decrease in the attraction between the nucleus and the valence electrons. Thus, Atomic radius decreases.
- Position of P Group − 2 Because it has 2 valence electrons i.e., 2, 8, 8, 2
Period − 4 Because it has 4 shells (2, 8, 8, 2)
Position of Q Group − 17 Because it has 7 valence electrons i.l., 2, 8, 7
Period − 3 Because it has 3 shells (2, 8, 7)
Molecular Formula is PQ2 because valency of P is 2 and that of Q is 1.
- In the case of a single-celled organism, no specific organs for exchange of gases are needed because the entire surface of the organism is in contact with the environment. But in multicellular organism, all the cells may not be in direct contact with the surrounding environment. Thus, diffusion is insufficient to meet the oxygen requirements of large multicellular organisms (human beings) because the volume of human body is so big that oxygen cannot diffuse into all the cells of the human body quickly.
- Release of CO2 and intake of O2 gives evidence that either photosynthesis is not taking place or its rate is too low. Normally during day time, the rate of photosynthesis is much more than the rate of respiration. So, CO2 produced during respiration is used up for photosynthesis hence CO2 is not released.
- Each piece regenerates into new Planaria.
- On the wet soil, it forms a bud, at its notches develop into new plants.
- It releases spores which germinate into new mycelium in moist conditions.
- Basic requirements of sexual reproduction is formation of male and female gametes and fusion of gametes or syngamy. Importance –
- Combination of DNA from two different individuals lead to increase in genetic variation in the organism
- This leads to diversity in the population which helps in natural selection.
- A. Ovary
- b. Anther
- c. Stamen
- d. Stigma
- A – Pollen grain
- B – Pollen tube
- C – Ovary
- D – Female gamete
- No, Rohit is incorrect because magnified image of an object cannot be formed by a concave lens ever.
- The object should be placed at 2F.
Image obtained is virtual, erect and diminished in case of concave lens.
- Slope gives resistance and it is higher for the curve corresponding to T2. So the resistance is higher for T2. Also resistance of a material is directly proportional to temperature.
- Resistance of resistor
- Given set of resistors should be connected in series to increase the equivalent resistance, i.e, Req =R1 + R2 + R3
- Here, R = 5Ω, R2 = 10Ω, R3 = 30Ω
In parallel combination, potential difference remains same.
When water is added to quick lime, a white powder of slaked lime is formed. It means it is a combination reaction. Also, a large amount of heat is released so it is an exothermic reaction.
The solution of the colour is green and that of the coating is reddish-brown. This is because iron being more reactive than Cu displaces Cu from CuSO4 and forms green coloured solution of FeSO4 and a reddish-brown layer of Cu get deposited.
To show that CO2 is given out during respiration, germinating seeds are used because they produce CO2 gas.
The function of cotyledons is to store food for the growth of embryo.
The reason given by A is correct. A spherical mirror, whose reflecting surface is curved inwards is called a concave mirror. When the face is placed close to concave mirror (so that the face is within the focus) the concave mirror produces enlarged and erect image
The overall range of the voltage is from 0 to 1.5 V and that of current is from O to = 0.5 A. We, therefore, prefer instruments that cover these ranges and also have a better least count.
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