# Class 10 Science Term 2 Sample Paper 2022 (Solved)

## Science Term 2 Sample Paper 2022 (Solved)

Class 10 Science Term 2 Sample Paper 2022, (Science) exams are Students are taught thru NCERT books in some of the state board and CBSE Schools. As the chapter involves an end, there is an exercise provided to assist students to prepare for evaluation. Students need to clear up those exercises very well because the questions inside the very last asked from those.

Sometimes, students get stuck inside the exercises and are not able to clear up all of the questions. To assist students, solve all of the questions, and maintain their studies without a doubt, we have provided a step-by-step NCERT Sample Question Papers for the students for all classes. These answers will similarly help students in scoring better marks with the assist of properly illustrated Notes as a way to similarly assist the students and answer the questions right.

# Class 10 Science Term 2 Sample Paper 2022

General Instructions:

(i) All questions are compulsory.

(ii) The question paper has three sections and 15 questions.

(iii) Section – A has 7 questions of 2 marks each; Section – B has 6 questions of 3 marks each; and Section – C has 2 case based questions of 4 marks each.

(iv) Internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.

### SECTION – A

1. The following table lists the boiling points of some alkanes having the general formula CnH2n+2 , where n = number of carbon atoms:

Can we say that they belong to the same homologous series? List any two characteristics of homologous series.      2

2. A letter ‘A’ consists of a uniform wire of resistance 1 ohm cm-1. The side of the letter are each 20 cm long and the cross-piece in the middle is 10 cm long while apex angle is 60o. Find the resistance of the letter between the two ends of the legs.

2

3. The variation of electronegativity values for the first 20 elements is shown in the graph below that demonstrates the trend in electronegativity of elements in the periodic table. The X-axis depicts the period and the Y-axis depicts electronegativity.

(A) With the help of the given graph, identify the trend of electronegativity for elements in the period.      1

(B) Why do you think all the periods do not show the normal gradation in electronegativity?           1

OR

(A) From the given graph, which period demonstrates maximum electronegativity.       1

(B) Arrange the following on the basis of increase in electronegativity: C, N, O, F and Cl.        1

4. (A) How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistors R1, R2, and R3 in series connected to a battery of V volts?     1

(B) Study the following circuit and find out:

(i) Current in 12 Ω resistor.     ½

(ii) Difference in the readings of A1 and A2, if any.        ½

OR

Answer the following questions:

(A) What is solenoid? Draw field lines of the magnetic field through a current carrying solenoid.        1

(B) If field lines of a magnetic field are crossed at a point, what does it indicate?         1

5. (A) What is meant by the series combination and parallel combination resistances ?          1

(B) In the circuit diagram given below five resistances of 5 Ω, 20 Ω, 15 Ω, 20 Ω and connected as given in figure to a 6V battery.

Calculate total resistance in the circuit.           1

6. Explain and justify the following statements.

(A) The existence of decomposers is essential in a biosphere.           1

(B) Flow of energy in a food chain is unidirectional.         1

7. Why is current induced in the secondary coil when current is changed in the primary coil?        2

OR

What is the role of split ring in an electric motor?            2

### SECTION – B

8. (A) What is a gene? How is it important in the living species?         1

(B) How is inheritance different in sexual and asexual mode of reproduction?         1

(C) Seema has 2 daughters. Can you analyze the situation genetically and provide a suitable explanation?        1

9. Observe the given figure of a leaf.

(A) What happens when the leaf shown in the figure falls with buds on it?         1 ½

(B) What are the advantages of the type of reproduction shown in figure? Give an example of such a reproduction.          1 ½

OR

The given figure represent (a) flower and (b) male reproductive system

(A) Write the names of those parts of flower which serve the same function as the following do in animals.           1 ½

(i) Testis

(ii) Sperm

(B) Among testis, scrotum, vas deferens, fallopian tube, prostate gland, which of the following is not a part of fig(b)?                  1 ½

10. (A) Define the term ‘isomers’.                1

(B) Draw two possible isomers of the compound with molecular formula C3H6O and write their names.            1

(C) Give the electron dot structures of the above two compounds.           1

11. (A) In a food chain 10,000 J of energy is available to the producer. How much energy would be available to the secondary consumers to transfer it to the tertiary consumers?       1

(B) What is the role of decomposers in the ecosystem?          1

(C) Why is improper disposal of waste a curse to the environment?          1

12. (A) Name two organisms which can reproduce asexually by regeneration.         1

(B) How is regeneration carried out in these organisms?            1

(C) Draw a diagram showing regeneration in any one organism.         1

OR

List three techniques that have been developed to prevent pregnancy. Which one the techniques is not meant for males? Suggest one contraceptive technique which help to prevent transmission of sexually transmitted diseases.          3

13. From the part of a periodic table, answer the following questions:

(A) Which of the elements will form covalent compounds? Give reasons.        1

(B) What is the number of valence electrons present in P, Q and R? Identify the trend in ionic radii for group I elements.            1

(C) Predict the formula of the oxide of W and Q.                1

### SECTION – C

This section has 02 case-based questions (14 and 15). Each case is followed by 03 sub-questions (A, B and C). Parts A and B are compulsory. However, an internal choice has been provided in part C.

14. A magnetic field will exert a force on a single moving charge, so that it will also exert a force on a current, which is a collection of moving charges. The force experienced by a wire of length L carrying a current l in a magnetic field B is given by force on a current-carrying wire: F= BIL sin θ.

(A) What will be the magnitude of the force on the current carrying conductor if the flow of electric current is parallel to the magnetic field?         1

(B) What do the forefinger, middle finger and thumb indicate as per Michael Faraday.             1

(C) (i) The graph below shows the variation of force acting on a conductor with current:

What do you interpret from the graph?          1

(ii) An electron enters a magnetic field at right angles to it as shown in fig.

OR

Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by strong magnetic field to your right side. What is the direction of magnetic field?           2

15. Inheritance from the previous generation provides both a common basic body design, and subtle changes in it, for the next generation. The original organism at the top will give rise to two individuals, similar in body design, but with subtle differences. Each of them, in turn, will give rise to two individuals in the next generation. Each of the four individuals in the bottom row will be different from each other.

(A) If a trait A exists in 10% of a population of an asexually reproducing species and B exists in 60% of the same population, which trait is likely to have arisen earlier?       1

(B) How does the creation of variations in a species promote survival?           1

(C) (I) Which of the processes, sexual reproduction or asexual reproduction, brings maximum variations in the offspring?           1

(ii) Give the pair of contrasting traits of the following characters in pea plant and mention which is dominant and recessive: Yellow seed and Round seed        1

OR

Give any two examples of human traits that shows variations.         2

## Solution of Sample Paper

### SECTION – A

1. Yes, the given compounds belong to the same homologous series as they have the same formula CnH2n+2.

Characteristics of homologous series are:

(1) All members of a homologous series can be represented by the same general formula. For example the general formula for alkanes is CnH2n+2, where n is the number of carbon atoms.

(2) They have similar chemical properties

(3) Any two adjacent homologues differ by – CH2 in their molecular formula.

(4) The difference in the molecular mosses of any two adjacent homologues is 14 u.

(5) All the compounds belonging to the same homologous series have similar chemical properties.

(6) The members of a homologous series show a gradual change in their physical properties with increase in molecular mass.

2. Let us look at the given circuit,

The net resistance can be found as follows:

Hence, the net resistance of the circuit is 26.67 Ohms

3. (A) Electronegativity increases as we move in a period and decreases as we move in a group as is evident from the graph.

(B) All periods do not show normal gradation in properties due to half filled and fully filled stability that few elements attain that lead to abnormal gradation in properties.

OR

(A) According to the graph, period 2 shows maximum electronegativity.

(B) Let us arrange the elements according to their position.

The increasing order of electronegativity is: C < N < O < Cl < F

Electronegativity increases in a period whereas it decreases in a group.

4. (A) (i) Take three resistors R1, R2 and R3 of different values and connect them in series with the help of a battery, ammeter and plug key as shown in the circuit diagram.

(ii) Plug in the key K and note the reading of the ammeter.

(iii) Change the position of the ammeter in between any of the resistors, say between R1 and R2, as shown after taking out the key.

(iv) Plug in the key again and note the ammeter reading.

(v) Repeat steps (iii) and (iv) for different positions of the ammeter.

Observation: We will observe that the ammeter reading remains same no matter where we connect the ammeter.

Conclusion: This shows that same current flows through every part of a circuit having resistances in series connected to a battery.

(B) (i) In the circuit the two resistors of 24Ω each are connected in parallel to each other. The equivalent resistance of the two resistances in parallel is given by 1/Rp = 1/R1 + 1/R R1 and R2 are the two resistances in parallel.

As this combination is in series with the 12 Ω resistance, the total resistance in the circuit is given by R = Rp + 12 = 12 = 24 Ω

Current is given by l = V/R = 6/24 A = 0.25A

The current flowing through the 12 Ohm resistance = 0.25A

(ii) Since the same current flows through every part of a circuit having resistances connected in series, both A1 and A2 will give the same reading 0.25 A

OR

(A) A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid Magnetic field around a current carrying solenoid is shown in the figure.

These appear to be similar to that of a bar magnet. One end of the solenoid behaves like North pole and the other end behaves Like the South pole. Magnetic field lines inside the solenoid are in the from of parallel straight lines. This means that the field is same at all the points inside the solenoid.

(B) No two field-lines are found to cross each other. If they did, it would mean that at the point at intersection the compass needle would point towards two directions, which is not possible.

5. (A) Resistors connected in series: In a series combination of resistors the current is the same in every part of the circuit. So same current flows through each resistor, i.e., there is only one path for the flow of current.

When several resistors are joined in series, the resultant resistance of the combination RS equals the sum of their individual resistances, R1, R2, R3.

RS = R1 + R2 + R3

Parallel combination of resistors: In a parallel circuit each resistor is placed in its own separate branch. A parallel circuit provides multiple paths for the current to flow.

The reciprocal of the equivalent resistance of a group of resistances joined in parallel is equal to the sum of the reciprocals of the individual resistances.

(B) To find total resistance in the circuit

Let RA be the value of total resistance in first combination i.e. 5 Ω and 20 Ω.

Let RB be the value of resistance in this combination. Then,

Total resistance across the circuit will be

6. (A) The existence of decomposers is essential in a biosphere because they break down complex organic substances into simple inorganic substances that can be absorbed by the plant. Thus, decomposers:

(1) replaced the soil naturally

(2) helps in removing the biodegrade waste.

(B) in a food chain the energy moves progressively through the various trophic levels, it is no longer available to the previous level (i.e., autotrophs) and the energy captured by the autotrophs does not go back to the solar inputs. Hence the flow of energy is unidirectional.

7. Galvanometer is an electromechanical instrument used to detect or indicate the presence of current by deflection in a circuit. It consists of a pointer which can move along a scale with zero marked at its centre and is attached to a moving coil.

OR

Split ring acts as a commutator. Its function is to reverse the direction of current in the loop after every half a rotation so that the coil rotates continuously in the same direction.

### SECTION – B

8. (A) Gene is the unit of inheritance. It is a part of the chromosome which controls the appearance of a set of hereditary characteristics.

(B) In case of a sexual mode of reproduction, when two germ cells combine, they will restore the normal number of chromosomes in the progeny, ensuring the stability of the DNA of the species. But in case of asexual mode, genes are obtained form only one parent.

(C) The woman has an ova having X chromosome. The male has a sperm with X as well as Y chromosomes. In this case, the male gamete with X chromosome fuses with the ova having ‘X’ chromosome. Thin results in a zygote.

9. (A) The leaf shown in the figure is of plant Bryophyllum. Bryophyllum can be reproduced by vegetative propagation by using a piece of its stem or leaves. The leaves of a Bryophyllum plant have special buds present in their margins which can get detached from the leaves, fall to the ground. Once the freshly produced plants touch the earth, they can separate from the leaves and grow into adult plants.

(B) Vegetative reproduction has several benefits, mainly because the developed offspring represents copies of their parent plants. If a plant has positives features the genetic information can be passed on to the next generation and the commercial growers may profit by cloning such plants in order to ensure their crops remain compatible financially. Budding in Hydra is also an example of vegetative propagation.

OR

(A) (i) Testis : Anther

In animals testes produces sperms whereas in plants anther produces pollen grains.

(ii) Sperm : Pollen grain

Sperm is the male gamete in animals whereas pollen grain is the male gamete in plants.

(B) Fallopian tubes are not a part of Fig (b), it represents the male reproductive system. The fallopian tube, also known as the oviduct, is one of two long, narrow ducts in the fermale abdominal cavity that transfer male sperm cells to the egg, provide a proper environment for fertilisation and transport the egg from the ovary to the uterus.

10. (A) Isomers are the compound with same molecular formula but different structural formula.

(B) Isomers of C3H6O:

CH3-CH2-CHO – Propanal

CH3COCH3 – Propanone or acetone.

(C) Propanal:

Propanone:

11. (A) 10 J of energy will be available to the secondary consumer to transfer to the tertiary consumers.

(B) The decomposers break down complex organic substances into simpler inorganic substances that go into the soil and are used again by the plants called nutrients cycle.

(C) Wastes pollute our environment, air, soil and water, and cause harmful effects on all living organisms.

12. (A) Hydra and Planaria reproduce asexually by regeneration.

(B) Regeneration is carried out by specialized cells. These cells, proliferate and make large number of cells. These large number of cells undergo changes to become various cell types and tissues. These changes take place in a systematic manner called development.

(C) Diagram showing regeneration in Planaria.

OR

The techniques developed to prevent pregnancy are:

(1) use of mechanical barners

(2) oral contraceptives

(3) surgical methods

Out of the above techniques, oral contraceptives are not meant for males.

Using a condom for the penis during sex helps to prevent transmission of sexually transmitted diseases.

13. (A) Covalent compounds are formed by sharing of electrons. This property is exhibited by group 14 elements. From the given table, W will form covalent compounds as it belongs to group 14.

(B) Elements P, Q and R belong to group 1 and thus all of them have one valence electrons. Group 1 elements are usually termed as alkali metals. The ionic radii also follows the same trend as atomic radii. These metals

have a single electron in its outermost shell so that they can easily lose this electron and form uni-positive ions. The ionic radii will increase as we move down in a group thereby P will have the smallest ionic radii and R will have the maximum ionic radii.

() W belongs to group 14 and thus has 4 valence electrons making its valency equal to 4. Q belongs to group 1 and thus has one valence electron making its valency equal to 1. The oxides of these elements will be:

### SECTION – C

14. (A) The force acting an the current carrying conductor will be zero if the current and the magnetic field are parallel to each other.

(B) The direction of force experienced by a current carrying conductor placed in a magnetic field is given by Fleming’s left hand rule which states that: stretch the forefinger, the central finger and the thumb of your left hand mutually perpendicular to each other. If the forefinger shows direction of the field and the central finger that of the current, then the thumb will point towards the direction of motion of the conductor, i.e force.

(C) (i) The force acting on a conductor increases linearly with increase in current. The graph between the force and current is a straight line which shows that force varies linearly with current.

(ii) The direction of force acting on the electron is into the page. The direction of force is perpendicular to the direction of the magnetic field and the current as given by Fleming’s left hand rule.

OR

Movement of an electron beam from back wall to front wall is equivalent to the flow of electric current from front wall to the back wall. Now the deflection of the beam towards right means direction of force is towards the right side. According to Fleming’s left hand rule, the magnetic field inside the chamber is in downward direction i.e. perpendicular to the plane of the paper and directed inwards.

15. (A) Trait B is likely to have arisen earlier because in asexual reproduction traits are carried from parents to offspring with least variations so since trait B has higher percentage it is likely to have arisen earlier.

(B) The variations provide stability to the population of various species by preventing them from getting wiped out during adverse conditions. The natural environment also changes, and variations in species which become suited to the environment help it to survive.

(C) (i) Sexual Reproduction

(ii)

OR

As skin colour and eye colour are polygenic features, they are the two human qualities that display variation. Polygenic traits are traits that are governed by two or more than two genes. Polygenic or quantitative inheritance refers to the inheritance or transmission of polygenic features.