10th Science Paper Solutions Set 3 : CBSE Delhi Previous Year 2013

General Instructions:
(i) The question paper comprises of two Sections, A and B. You are to attempt both the sections.
(ii) All questions are compulsory.
(iii) All question of Section-A and all questions of Section-B are to be attempted separately. 
(iv) Question numbers 1 to 3 in Section-A are one mark questions. These are to be answered in one word or in one sentence. 
(v) Question numbers 4 to 7 in Sections-A are two marks questions. These are to be answered in about 30 words each.
(vi) Question number 8 to 19 in Section-A are three marks questions. These are to be answered in about 50 words each.
(vii) Question numbers 20 to 24 in Section-A are five marks questions. These are to be answered in about 70 words each.
(viii) Question numbers 25 to 42 in Section-B are multiple choice questions based on practical skills. Each question is a one mark question. You are to select one most appropriate response out of the four provided to you.
Q1 :

How many horizontal rows are there in the modern periodic table and what are they called? (1)


Answer :

There are 7 horizontal rows in the modern periodic table. They are called periods.

Q2 :

List any two factors that could lead to speciation. (1)


Answer :

Natural selection and genetic drift could lead to speciation.

Q3 :

Mention one negative effect of our affluent life style on the environment. (1)


Answer :

Exploitation and overconsumption of natural resources will ultimately result in their scarcity.

Q4 :

Mention the two functions of human testis. (2)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q5 :

Every one of us can do something to reduce our consumption of various natural resources. List four such activities based on 3-R approach. (2)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q6 :

“A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw labelled ray diagram to justify the statement. (2)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q7 :

We often observe domestic waste decomposing in the bylanes of residential colonies. Suggest ways to make people realise that the improper disposal of waste is harmful to the environment. (2)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q8 :

Name the oxidising agent used for the conversion of ethanol to ethanoic acid. Distinguish between ethanol and ethanoic acid on the basis of (i) litmus test, (ii) reaction with sodium carbonate (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q9 :

(a) Differentiate between alkanes and alkenes. Name and draw the structure of one member of each. (3)

(b) Alkanes generally burn with clean flame. Why?


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q10 :

Given below are some elements of the modern periodic table : (3)

4Be, 9Fe, 14Si, 19K, 20Ca

(i) Select the element that has one electron in the outermost shell and write its electronic configuration.

(ii) Select two elements that belong to the same group. Give reason for your answer.

(iii) Select two elements that belong to the same period. Which one of the two has bigger atomic size?


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q11 :

An element X (atomic number 17) reacts with an element Y (atomic number 20) to form a compound. (3)

(a) Write the position of these elements in the modern periodic table.

(b) Write the formula of the compound formed.

Justify your answer in each case.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q12 :

“The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it.” Justify this statement with the help of flow chart showing determination of sex of a newborn. (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q13 :

Tabulate two distinguishing features between acquired traits and inherited traits with one example of each. (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q14 :

Write two examples each of sexually transmitted diseases caused by (i) virus, (ii) bacteria. Explain how the transmission of such diseases be prevented ? (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q15 :

(a) Explain the process of regeneration in Planaria. (3)

(b) How is regeneration different from reproduction?


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q16 :

An object of height 5 cm is placed perpendicular to the principal axis of a concave lens of focal length 10 cm. Use lens formula to determine the position, size and nature of the image if the distance of the object from the lens is 20 cm. (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q17 :

Mention the types of mirrors used as (i) rear view mirrors, (ii) shaving mirrors. List two reasons to justify your answers in each case. (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q18 :

State the difference in colours of the sun observed during sunrise/sunset and noon. Give explanation for each. (3)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q19 :

(a) What is an ecosystem? List its two main components. (3)

(b) We do not clean ponds or lakes, but an aquarium needs to be cleaned regularly. Explain.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q20 :

(a) Write the function of placenta in human females. (5)

(b) List four ways of preventing pregnancy. State two advantages of using such preventive methods.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q21 :

(a) Identify A, B and C in the given diagram and write their functions. (5)

(b) Mention the role of gamete and zygote in sexually reproducing organisms.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q22 :

(a) A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length. (5)

(b) We see advertisements for eye donation on television or in newspapers. Write the importance of such advertisements.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q23 :

State Snell’s law of refraction of light. Write an expression to relate refractive index of a medium with speed of light in vacuum.

The refractive index of a medium ‘a’ with respect to medium ‘b’ is 2/3 and the refractive index of medium ‘b’ with respect to medium ‘c’ is 4/3. Find the refractive index of medium ‘c’ with respect to medium ‘a’. (5)


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q24 :

(a) Define the term ‘isomers’. (5)

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

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


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q25 :

A student obtained a sharp image of a burning candle, placed at the farther end of a laboratory table, on a screen using a concave mirror. For getting better value of focal length of the mirror, the subject teacher suggested him for focusing a well illuminated distant object. What should the student do? (1)

(A) He should move the mirror away from the screen.

(B) He should move the mirror slightly towards the screen.

(C) He should move the mirror as well as the screen towards the newly selected object.

(D) He should move only the screen towards the newly selected object.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q26 :

A student focussed the image of a distant object using a device ‘X’ on a white screen ‘S’ as shown in the figure. If the distance of the screen from the device is 40 cm, select the correct statement about the device. (1)

(A) The device X is a convex lens of focal length 20 cm.

(B) The device X is a concave mirror of focal length 40 cm.

(C) The device X is a convex mirror of radius of curvature 40 cm.

(D) The device X is a convex lens of focal length 40 cm.


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q27 :

Study the following ray diagrams: (1)

(I)

(II)

(III)

(IV)

The diagrams showing the correct path of the ray after passing through the lens are:

(A) II and III only

(B) I and II only

(C) I, II and III

(D) I, II and IV


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q28 :

Out of the five incident rays shown in the figure find the three rays that are obeying the laws of refraction and may be used for locating the position of image formed by a convex lens:

(A) 1, 2 and 3

(B) 2, 3 and 4

(C) 3, 4 and 5

(D) 1, 2 and 4


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q29 :

Select from the following the best set-up for tracing the path of a ray of light through a rectangular glass slab: 1

(A) I

(B) II

(C) III

(D) IV


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q30 :

After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below: (1)

S. No.

i

i

e

I

30°


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q31 :

In an experiment to trace the path of a ray of light through a glass prism for different values of angle of incidence a student would find that the emergent ray: (1)

(A) is parallel to the incident ray

(B) perpendicular to the incident ray

(C) is parallel to the refracted ray

(D) bends at an angle to the direction of incident ray


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q32 :

While performing the experiment to trace the path of a ray of light passing through a glass prism, four students marked the incident ray and the emergent ray in their diagrams in the manner shown below. (1)

(A) I

(B) II

(C) III

(D) IV


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q33 :

Study the different conclusions drawn by students of a class on the basis of observations of preserved/available specimens of plants and animals. (1)

I. Potato and sweet potato are analogous organs in plants.

II. Wings of insects and wings of birds are homologous organs in animals.

III. Wings of insects and wings of bats are analogous organs in animals.

IV. Thorns of citrus and tendrils of cucurbita are analogous organs in plants.

The correct conclusions are:

(A) I, and II

(B) II and IV

(C) I and III

(D) III and IV


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q34 :

You have potato, carrot, radish, sweet potato, tomato and ginger bought from the market in your jute bag. Identify two vegetables to represent the correct homologous structures. (1)

(A) Potato and tomato

(B) Carrot and tomato

(C) Potato and sweet potato

(D) Carrot and radish


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q35 :

In the figure, the parts marked A, B and C are sequentially: (1)

(A) Plumule, Radicle and Cotyledon

(B) Radicle, Plumule and Cotyledon

(C) Plumule, Cotyledon and Radicle

(D) Radicle, Cotyledon and Plumule


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q36 :

Select the correct statements for the process of budding in yeast: (1)

I. A bud arises from a particular region on a parent body.

II. A parent cell divides into two daughter cells, here the parental identity is lost.

III. Before detaching from the parent body a bud may form another bud.

IV. A bud when detaches from the parent body grows into a new individual.

(A) I, II and III

(B) II, III and IV

(C) III, IV and I

(D) IV, I and II


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q37 :

A student after observing a slide showing different stages of binary fission in Amoeba draws the following diagrams. However these diagrams are not in proper sequence:

The correct sequence is:

(A) I, V, IV, III, II

(B) I, III, IV, V, II

(C) I, V, III, IV, II

(D) I, IV, V, III, II


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q38 :

Read the following statements: (1)

I. When a red litmus paper is dipped into reaction mixture of a saponification reaction, it turns blue and the reaction is exothermic.

II. When a blue litmus paper is dipped into reaction mixture of a saponification reaction, its colour does not change and the reaction is exothermic.

III. When a red litmus paper is dipped into reaction mixture of a saponification reaction, its colour does not change and the reaction is endothermic.

IV. When a blue litmus paper is dipped into reaction mixture of a saponification reaction, its colour does not change and the reaction is endothermic.

Which of the above statements are correct:

(A) I, and II

(B) II and III

(C) III and IV

(D) I and IV


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q39 :

A student prepared 20% sodium hydroxide solution in a beaker containing water. The observations noted by him are given below. (1)

I. Sodium hydroxide is in the form of pellets.

II. It dissolves in water readily.

III. The beaker appears cold when touched from outside.

IV. The red litmus paper turns blue when dipped into the solution.

The correct observations are:

(A) I, II, and III

(B) II, III and IV

(C) III, IV and I

(D) I, II and IV


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q40 :

Hard water required for an experiment is not available in a school laboratory. However, following salts are available in the laboratory. Select the salts which may be dissolved in water to make it hard for the experiment. (1)

(1)

Calcium Sulphate

(2)

Sodium Sulphate

(3)

Calcium Chloride

(4)

Potassium Sulphate

(5)

Sodium Hydrogen Carbonate

(6)

Magnesium Chloride

(A) 1, 2 and 4

(B) 1, 3 and 6

(C) 3, 5 and 6

(D) 2, 4 and 5


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q41 :

In an experiment to study the properties of acetic acid a student takes about 2 mL of acetic acid in a dry test tube. He adds about 2 mL of water to it and shakes the test tube well. He is likely to observe that: (1)

(A) the acetic acid dissolves readily in water

(B) the solution becomes light orange

(C) water floats over the surface of acetic acid

(D) acetic acid floats over the surface of water


Answer :

Please Register/Login to get access to all solutions Facebook Login
Q42 :

A student takes 2 mL acetic acid in a dry test tube and adds a pinch of sodium hydrogen carbonate to it. He makes the following observations: (1)

I. A colourless and odourless gas evolves with a brisk effervescence.

II. The gas turns lime water milky when passed through it.

III. The gas burns with an explosion when a burning splinter is brought near it.

IV. The gas extinguishes the burning splinter that is brought near it.

The correct observations are:

(A) I, II, and III

(B) II, III and IV

(C) III, IV and I

(D) IV, I and II


Answer :

Please Register/Login to get access to all solutions Facebook Login

10th Science Paper Solutions Set 1 : CBSE Delhi Previous Year 2013 will be available online in PDF book soon. The solutions are absolutely Free. Soon you will be able to download the solutions.