Class x science

Class- X Science Time: 3 Hrs M.M. 80 General Instructions: a. The Questions paper comprise of five sections: A, B, C, D, E. You are to attempt all the sections. b. All questions are compulsory. c. Internal choice is given in section B, C, D & E d. Question numbers 1 and 2 in section -A are one mark questions. These are to be answered in about 1 (one) word each. e. Question numbers 3 to 5 in section-B are two mark questions. These are to be answered in about 30 words each. f. Question numbers 6 to 15 in Section-C are three marks questions. These are to be answered in about 50 words each. g. Question numbers 16 to 21 in section-D are five marks questions. These are to be answered in about 70 words each. h. Question numbers 22 to 27 in section E are bases practical skills. Each question in a two marks question. These are to be answered in brief. Section-A Q1. What is the full form of CFC and UNEP? (½+ ½) Q2. Name the group of animals which derive nutrition from plants or animals without killing them. (1) Section-B Q3. How does binary fission differ from multiple fission? (1+1) Q4. How is MgCl2 formed by the transfer of electrons? What are the ions present in this compound? (1+1) Q5. The refractive indices of glass and water with respect to air are 3/2 and 4/3 respectively. If speed of light in glass is 2 X 108 m/s, find the speed of light in water. (2) OR Draw a ray diagram to show refraction of light through a glass prism and show angle of incidence and angle of deviation. (2) Q6. What happens when Zinc is added to the aqueous solution of copper sulphate? Give a balanced equation for the reaction. Name and define the type of reaction involved in the above change. (1+1+1) Q7. What happens when dilute Hydrochloric acid is added to the following? Write balanced chemical equations: (1+1+1) a) Calcium oxide b) Zinc granules c) Baking Soda OR Page 2 of 4 A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water. Identity the compound. Write the chemical equation for its preparation. For what purpose is it used in hospitals? (1+1+1) Q8. a) Name a hormone which is injected to a diabetic patient. (1+2) b) If the cerebellum is not functioning properly, what activities of our body are affected? Q9. What substances are contained in the gastric juice? What are their functions? (1 ½ + 1 ½ ) Q10. Write the number of periods and groups the Modern periodic table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we go down a group. (1+1+1) Q11. An object 5 cm in length is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position of the image, its nature and size. Also draw its ray diagram. (1+1+1) OR How are power and focal length of a lens related? You are provided with two lenses of focal length 20 cm and 40 cm respectively. Calculate their power and which lens will you use to obtain more convergent light? (1+1+1) Q12. a) Why are coils of electric toaster and electric irons are made of alloy rather than a pure metal? (1+2) b) What is resistivity and what is its unit? Q13. An electric iron draws a current of 4A from 220V supply line. When voltage of supply is changes, then iron draws a current of 2A, what is the new voltage applies? (1+2) Q14. Name the main constituent of biogas. Why bio-gas is considered an ideal fuel for domestic use? (1+2) Q15. What are trophic levels? Explain why a food chain should consist of only 3-4 trophic levels. (1+2) OR Distinguish between biodegradable and non-biodegradable pollutants. Give Two examples of each. (2+1) SECTION-D Q16. (2+3) a) What are amphoteric oxides? Give two examples of amphoteric oxides. b) What happens when calcium reacts with water? Write a chemical equation for the reaction. Why calcium starts floating on the surface of water? Q17. Identify the functional group and give IUPAC names of the following compounds. ( Page 3 of 4 c) CH3 COCH3 d) CH3-CH2- CH2-OH e) CH3 -CH2 -CH2 –Cl OR An organic compound A on heating with Conc. H2SO4 forms a compound B which on addition of hydrogen in presence of Nickel forms a compound C. One molecule of compound C on combustion forms CO2 and H2O. Identify A, B and C. Write the chemical equation for all the chemical reactions involved. (3+2) Q18. (2+3) a) Draw a well labelled diagram of germination of pollen on stigma. b) What do you mean by unisexual and bisexual flowers? Give one example of each. Q19. (3 +1+1) a) Draw a neat diagram of excretory system of human beings and label the following: i. Kidney ii. Ureter iii. Urinary bladder iv. Urethra b) How is urine produced in human beings? c) Name two excretory products other than O2 and CO2 in plants. OR (3+2) a) “The sex of the children will be determined by what they inherit from their father.” Draw a flow chart showing determination of sex of a new born baby to justify this statement. b) Name the plant used by Mendel for his experiments. What is the ratio of F2 Generation in a monohybrid cross? Q20. (3+2) a) How is Rainbow formed? b) Why do stars twinkle? Q21. (3+2) a) State one main difference between AC and DC. Why AC is preferred over DC for long range transmission of electric Power? Name one source each of DC and AC. b) What is electromagnetic induction? How does a moving magnet can be used to produce electric current? OR (2+2+1) a) Describe an activity to demonstrate the pattern of magnetic field lines around a straight conductor carrying current. Page 4 of 4 b) State the rule to find the direction of magnetic field associated with a current carrying straight conductor. c) What is the shape of a current carrying conductor whose magnetic field pattern resembles that of a bar-magnet? SECTION-E Q22. One drop of each of HCl, NaOH is put on Separate PH papers and the pH is noted. Which one has lower pH and which one has larger? What should be the colour of pH paper in both the solutions? (2) OR Write your observation when you add quicklime in water contained in a beaker. Write the balanced chemical equation and the type of reaction. (2) Q23. Why the angle of refraction is less than angle of incidence when a ray of light passes obliquely from air to glass slab? (2) Q24. In an experimental setup for determination of resistance of a given resistor, it is advised to take out the plug from the key when the observations are not being taken. Why? (2) Q25. Why do we use KOH solution and germinating seeds in an experiment to show that CO2 gas is released during respiration? (2) Q26. Draw well labelled diagrams to show various stages of binary fission in Amoeba. (2) OR Name the process by which hydra reproduces. Draw diagrams to show reproduction in hydra in sequence. (2) Q27. What is the function of guard cells in stomata? Why is the number of stomata more on the lower surface of a leaf? (2)