SUMMATIVE ASSESSMENT-II SCIENCE Time : 3 hours Maximum Marks: 80
SECTION-A
3. An object is placed perpendicular to the principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 30 cm. Find (I) the position (ii) the magnification and (iii) the nature of the image formed. OR 4. One half of a convex lens is covered with a black paper. Will such a lens produce an image of the complete object? Support your answer with a ray diagram. 5. An object 5 cm high is held 25 cm away from a converging lens of focal length 10 cm. 1. Draw the ray diagram and 2. Calculate the position and size of the image formed. 3. What is the nature of the image.
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1. If 4a2x2 + 4abx + = 0 has equal roots of x, then find the value of k.
2. Two positive numbers differ by 3 and their product is 504. Find the numbers. 3. The length of a tangent from a point A at a distance 5 cm from the centre of the circle is 4 cm. Find the diameter of the circle. 4. Two tangents PQ and PR are drawn from an external point P to a circle with centre O. Prove PROQ is a cycle quadrilateral. 5. Determine the ratio in which the point P(x, -2) divides the join of A(-4, 3) and B(2, -4). Also find the value of x. 6. Area of a sector of a circle of radius 36 cm is 54p cm2. Find the length of corresponding arc of sector. 7. Two cubes each of edge 4 cm are joined face to face. Find the surface area of the resulting cuboid. 8. A dice is thrown once. Find the probability of getting: (a) a prime number (b) a number divisible by 2Find the sum of all two digit positive numbers divisible by Question numbers 19 to 28 carry 3 marks each. 9. In an A.P. the first term is 24, the last term is 29 and the sum of all its term is 150. Find its common difference. 10. For what values of k does (k-12)x 2 + 2(k-12)x + 2= 0 has equal roots ? X Maths guess questions for CBSE board exam March 2012 Guess Paper – 2012 Class – X Subject –Social Science
Answer the following questions:- 1. When was the Champaran Movement started by Mahatma Gandhi and why? 1mark 2. Why was policy of non-cooperation adopted by Gandhiji and Congress? 1-mark 3. Why did the Indians oppose the Simon Commission? 1-mark 4. When was a satyagraha organized in the kheda district of Gujrat and why? 1-mark 5. Why did the industrial workers not join Civil Disobedience Movement? 1-mark 6. How did people belonging to different communities, regions or language groups develop a sense of collective belonging in India? 3-marks 7. Who formed the Swaraj Party and why? 3-marks 8. Describe the policy of the government during the first phase of the Civil Disobedience Movement. 3-marks 9. Describe the views of Mahatma Gandhi on untouchability. 3-marks 10. Describe the events leading to the Salt March and the Civil Disobedience Movement in 1930 3-marks 11. Why Gandhiji decided to withdraw the Non-Cooperation Movement? 4-marks 1. What do you understand by modern nationalism in Europe? 1-mark 2. Name the famous brothers who were Muslim leaders in 1919. 1-mark 3. When and why a satyagraha movement was organized in Ahmedabad? 1-mark 4. Who was the spiritual head of the Islamic world? 1-mark 5. Describe Gandhiji’s view on the role of women in life. 1-mark 6. Name two prominent leaders who formed the Swaraj Party within the Congress. What was the aim of the Swaraj Party? 3-marks 7. What do you understand by boycott? Why was foreign cloth boycotted during Non-Cooperation Movement? 3-marks 8. Describe Mahatma Gandhi’s view on satyagraha. 3-marks 9. Describe the events leading to Non-Cooperation Movement in support of Khilafat as well as for Swaraj 3-marks 10. Write a short note on Simon Commission. 3-marks 11. How the first World War helped in the growth of the National Movement in India?4-marks Class – X Subject –History (a) “ A large city population was thus both a threat and an opportunity.” Justify this statement. (b) What led to the major expansion of Bombay’s population in the mid-18th century ? (c) Who wrote “The Bitter Cry of Outcast London’ and when ? d) What do you know about ‘London Season’ ? e) Explain in brief the history of Land Reclamation in Mumbai. (f) Explain the social change that took place in the 19th century which resulted into political movements. (g) When and where was the very first section of the underground railway in the world opened ? Why did people oppose it ? (h) What forms of entertainment came up in England came up in England to provide leisure activities for the people ? (i) “Many felt that the ‘Iron Monsters’ added to the mess and unhealthiness of the city.” Explain. (j) Who developed the concept of the principle of the Garden city of New Earswick ? Mention its features. (k) Who did the first social survey of low skilled London workers in the East End of London ? Explain his suggestions in the context of what he surveyed about. (l) ‘London grew as a crime flourished city’. Discuss the statement. “ Bombay films have contributed in a big way to produce an image of the city as a blend of dream and reality of slums and star bunglows.” Explain. social science_sample_paper x-1 social_science_sample_paper_x-2 social_science_sample_paper_x-3 social_science_sample_paper_x-4 social_science_sample_paper_x-5 social_science_sample_paper_x-6 social_science_sample_paper_x-7 social_science_Study material and N0tes ![]() CLASS X SCIENCE (Physics+Chemistry) SUMMATIVE ASSESSMENT TERM II 2012 SAMPLE PAPER- I 1. Why carbon forms strong bonds with other carbon atoms, hydrogen, oxygen, nitrogen or sulphur? 2. Name the part of eye responsible for conversion of light into electrical impulses. 3. a. How does valency vary in a group on going from top to bottom? b. How does atomic size vary in a period on going from left to right? 4. Write one property of hydrogen which makes it resemble with (a) Alkali metals (b) Halogens 5. a Arrange the following common substances in the increasing order of refractive indices. Ice, Kerosene, Glass, Diamond, Alcohol, Waterb. Is it necessary that optically dense medium possesses greater mass density? Give an example. 6. On reaction with sodium hydroxide, X yielded Ethanoic acid and ethanol.(a) Give the IUPAC name of X? (b) Name the reaction. (c) Give a chemical reaction for the above reaction. 7. (a) How does the electronic configuration of an atom related to its position in the Modern periodic table? Give one example. (b) Why nitrogen is more electronegative than phosphorus? 8. A concave length has focal length of 25 cm. At what distance should the object from the lens be placed so that if it forms an image at 20 cm distance from the lens? Also find the magnification produced by the lens. 9. Give an explanation for the formation of a rainbow. 10. How are we able to see distant and near by objects clearly? Which part of eye helps in changing curvature of lens? Why no image is formed at blind spot? 11.(a) Why magnification is taken negative for real images and positive for virtual images? (2) (b) Why convex mirror is used in rear view mirrors and not concave mirror? (2)(c) Power of concave lens is 4.5 D. Find its focal length. (1) 12.(a) Find the size, nature and position of image formed when an object of 1 cm is placed at a distance of 15 cm from a concave mirror of focal length 10 cm. (3) (b) Why does light travels faster in water in comparison to kerosene. (Refractive index of water and kerosene are 1.33 and 1.44 respectively) (2) 13 . a. Which property of carbon leads to formation of large number of compounds? Define itb. What is the functional group in the following molecules? i. CH3CH2CH2OH ii. CH3COOH c. Which of the following formula represents a saturated hydrocarbon? CnH 2n, C nH2n+1 Cn H2n+2 Cn H2n-2d. What happens when methane is burnt in oxygen?e. Why is the conversion of ethanol to Ethanoic acid an oxidation reaction? 14. a. Give three points to distinguish between alkenes and alkynes. b. Explain the mechanism of cleaning action of detergents CLASS X SCIENCE (Physics & Chemistry) SUMMATIVE ASSESSMENT TERM II 2012 SAMPLE PAPER- I (solution) 1. Due to small size and presence of four valence electrons, carbon forms strong bonds with other carbon atoms, hydrogen, oxygen, nitrogen or sulphur. 2. Retina. 3. a. Valency remains same on moving from top to bottom in a particular group. This is because the outermost electronic configuration of all the elements in a group remains same. b. Atomic size decreases on moving from left to right in a period. This is because the number of shells remains same but the nuclear charge increases. Due to this, electrons are pulled closer to the nucleus and decrease the atomic size. 4. Resemblance with alkali metals: Hydrogen has the same outermost electronic configuration as that of alkali metals.Resemblance with halogens:Hydrogen exists as diatomic molecule as halogens. 5. a. In the order of increasing refractive indices:Ice; Water; Alcohol; Kerosene; Glass; Diamond b. No, it is not always necessary. For e.g., kerosene and turpentine oil having high refractive index are optically dense than water. But its mass density is less than that of water. That is why oil floats on the surface of water. 6. (a) X is ethyl Ethanoate. (b) It is Saponification reaction. (c) CH3COOC2H5 + Na OH -----------> C2H5OH + CH3COOH 17. (a) By the electronic configuration of an atom we can identify the group and period to which the atom belongs. For example - Oxygen has atomic number 8. Its electronic configuration is 2,6. As it can gain two electrons to complete its octet, so it belongs to group 16 Also, since the electrons are filled in two shells. So. Oxygen belongs to the second period. (b) As we move down the group, electro negativity of elements decreases as the atomic size increases. Nitrogen is placed above phosphorus in group 15. So, nitrogen is more electronegative than phosphorus. 8. A concave lens always forms a virtual, erect image on the same side of the object.v = -20 cm, f = -25 cm, u = ? 1/v -1/u = 1/f 1/u = 1/(-20) – 1/(-25) 1/u = -1/100 u= -100cm Thus object distance is 100 cm. Magnification= v/u = -20/ (-100) = + 0.5 1 Thus image is erect, virtual and is half of the size of object. 9. Formation of rainbow: The rainbow is formed in the sky when sun shines and it is raining at the same time. The raindrops in the atmosphere act like many small prisms. As white light enters and leaves these raindrops the various colours present in white light are refracted by different amount due to which an arch of seven colours called rainbow is formed in the sky. Diagram 10. (a) Accommodation (b) Ciliary muscles. (c) No image is formed at the blind spot because no nerve cells are present there to carry the information of image to the brain. 11. (a) Distance measured upward and perpendicular to the principal axis are taken as positive. Distances measured down ward and perpendicular to the principal axis are taken as negative. So magnification for a real image is taken negative and for a virtual image it is taken as positive. (b) A convex lens forms a virtual and small sized image of the object and concave mirror forms real and inverted image. Thus by using convex mirror we can get view of wider field which is not possible in case of a concave mirror. (c) Power = 1/Focal length Or Focal length = 1/Power f= 1/4.5 f = 0.22 cm 12. (a) Object distance, u = -15 cm Image distance, v= ? Focal length, f = -10 cm Mirror formula, 1/v + 1/u = 1/f 1/v + 1/ (-15) = 1/(-10) 1/v = -1/10 + -/15 1/v = -3+2/30 1/v = -(1/30) Thus the position of image is formed on left hand side in front of the concave mirror at a distance of30 cm, its nature will be real and inverted. Size of image m= -v/u m= - [(-30)/(-15)] m= -2.Thus the size of image is 2 cm and image is real and inverted. (b) Refractive index of a medium= Speed of light in air/ Speed of light in medium.So, speed of light in medium= speed of light in air/ refractive index Thus speed of light will be maximum in medium having lowest refractive index. Therefore speed of light is more in water in comparison to kerosene. 13. (a) Catenation The property of carbon atom to link with other carbon atoms to form large molecules is called as catenation. b. i. Functional group is –OH group. ii. Functional group is –COOH group. C. Cn H2n+ 2 represents a saturated hydrocarbon. d. Methane burns in oxygen with formation of carbon dioxide and water. CH4 + 2O2 -----------> CO2 + 2H2O e. Conversion of ethanol to Ethanoic acid is an oxidation reaction because oxygen is added to ethanol and Ethanoic acid is formed. CH 3CH2 OH + O2 -----------> CH3 COOH + H2 O Ethanol Ethanoic acid 14. a. No. Alkene (1) Unsaturated hydrocarbon containing a double bond between two carbon atoms are known as alkenes. (2) General formula is CnH2n Example: Ethene, Propene Alkynes: Unsaturated hydrocarbons containing a triple bond between two carbon atoms are known as alkynes. (2) General formula is CnH2n -2 (3) Example: Ethyne, Propyne b. A detergent molecule consists of two ends – (a) hydrocarbon tail which is hydrophobic (water repelling) and (b) polar head which is hydrophilic (water attracting or loving). When a detergent is dissolved in water, the hydrocarbon tail aligns itself towards the dirt and ionic part aligns itself towards the water. The molecules gather together as clusters, called micelles. When water is agitated, the dirt suspended in the micelles is easily rinsed away. Thus, the cloth gets cleaned. CBSE BOARD EXAM SPECIAL Class X: Sample Question Papers for Term I (September ) Class X: Sample Question Papers for Term I (September ) Class IX: Sample Question Papers for Term I (September ) Class IX: Sample Question Papers for Term I (September ) Class X: Sample Question Papers for Term II (March ) Class X: Sample Question Papers for Term II (March ) Class IX: Sample Question Papers for Term II (March ) Class IX: Sample Question Papers for Term II (March ) Class IX-X: Value Based Questions 1. To prevent the misuse of alcohol which poisonous substance is added in it?
(a. Methanol (b.) Ethanol (c.) Butanol (d.) Ether 2. Which Substance is used as pickles preservative? (a.) Ether (b.) Acetic acid (c.) Vinegar (d.) Ethanoic acid 3. Carboxylic acids are called. (a.) Inorganic Compound (b.) Organic Compound (c.) Hydrocarbon Compound (d.) Acetic acid 4. In modern periodic table how many columns are vertically arranged? (a.) 16 (b.) 18 (c.) 14 (d.) 20 5.In what way Mendeleev's published his periodic table. (a.) Radio (b.) Television (c.) Magazine (d.) Newspaper 6.In an experiment to determine the focal length of a convex lens, a student obtained a sharp inverted image of distant tree on the screen behind the lens. He / She then removed the screen and looked through the lens in the direction of object. She / He will see. - (a.) An inverted image of tree at focus of lens. (b.) No Image as the screen has been removed (c.) A blurred image on the wall of laboratory (d.) An erect image of the tree on the tree on the lens 7. For doing experiment on verifying the Causes of reflection of sound. A student sets up his apparatus as shown. The experiment is more likely is get performed successfully if the screen shown is (a.) Well polished plane mirror (b.) Wooden board with many holes in it (c.) A foam padded board (d.) A sheet of pure white cloth 8. The focal length of a concave mirror depends on it. (a.) Size (b.) Radius of curvature (c.) Pole (d.) Center of curvature 9.The diameter of the reflecting surface of spherical mirror is called. (a.) Focal length (b.) Radius of curvature (c.) Aperture (d.) Principal focus 10. To form complete image of the object height of the mirror is. (a.) Double (b.) Half (c.) One – Fourth (d.) Same size as object 11. The magnification of plane mirror is(a.) -1 (b.) +1 (c.) 0 (d.) Infinitive 12. . What is catenation ? 13. Name the structure of diamond and graphite? 14. Which organic compound made in laboratory. By whom and when? 15. Name that inorganic compound by which organic compound is formed also write their formula. 16. Why carbon atoms always form covalent bond? 17. Name two elements which shows catenation but they are unstable? 18. Why kitone group can never occur at the end of carbon chain? 19. Why do substances burn with flame? Name their types? 20. Why mixture of acetylene and air is not used for welding? 21. People use a variety of methods to wash cloths. Usually after adding the shop, they beat the cloths on a stone or beat it with a paddle, scruib with a brush or mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes? 22. Besides gallium, which other elements have since been discovered that were left by Mendeleev in his periodic table? 23. Explained why stars twinkle but why plants do not twinkle? 24. Why do we have two eyes for vision and not just one? 25. When and by whom dispersion of light experimentally discovered? For more Sample CBSE Paper Visit link |
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