Q 1. Give one use of anhydrous calcium chloride. (1)
Q 2. Why is electrolysis of distill water is not possible. How it is made possible. (1)
Q 3. A student obtains resistance of 16Ω, 12Ω, 4Ω, 3Ω only by using two metallic resistances wires
either separately or joined together. What is the value of each resistor? (1)
Q 4. Give a condition when Snell law fails. (1)
Q 5. Why is series arrangement not satisfied for domestic circuit? (1)
Q 6. A current through a horizontal power line flows east to west direction. What is the direction of magnetic field at a point directly below it? Which rule you will apply in this regard. (1)
Q 7. A drop of water is poured over a white powdery substance ‘J’. I was observed the ‘J’ turns in blue substance ‘K’.
- What is white powdery substance ‘J’?
- What is blue coloured substance ‘K’ and give nature of ‘K’. Give equation to convert ‘K’ to ‘J’. (2)
Q 8. A nichrome wire has a resistance of 5Ω. Find the resistance of another nichrome wire, whose length is four times and area of cross section is three times the first wire. (2)
Q 9. What is meant by frequency of an alternate current?
What is its value in India?
Why is alternate current considered to be advantageous over direct current for long-range transmission of electric energy? (2)
Q 10. What is rainbow? How it is caused. (2)
Q 11. A compound ‘X’ gained importance as a important symbol in our struggle for freedom. This movement was popularly known as Mahatama Gandhi’s Dandi March. Compound ‘X’ was found to possess m.p. =1074K
- Identify the compound.
- Write the nature of chemical bond found in between atoms of this compound.
- Write any two physical properties other than its mp. & b.p. (3)
Q 12. Define Modern Periodic law. Who gave the concept of this law?
How does electronegativity of an element vary on moving from-?
- Left to right in a period.
- From top to bottom in a group. (3)
Q 13. A straight copper conductor, whose ends are connected to a sensitive galvanometer, is moved up and down in a strong magnetic field.
- State your observations and name the phenomenon.
- What is the nature of induced current generated in the conductor?
- What kind of energy transformation takes place in the above experiment and name the scientist who done above experiment. (3)
Q 14. (a) Draw a flow chart to show steps involved in extraction of metals from ore.
(b) Draw a labeled diag showing action of steam on metals. (3)
Q 15. (a) A mirror forms 2 times real and inverted image when object is placed at a distance of 10 cm. At what distance should an object be placed so that image is 3 times virtual and erect?
(b) Define power of lens and write its S.I. unit (5)
Or
Give reason for the following:
- The sky appears to be blue during daytime to a person on earth.
- The sun appears circular during evening hours.
- The stars appear to twinkle.
- The planets do not twinkle.
- Danger signals are made of red colour.
Q 16.. (a) An organic compound ‘Y’ is commonly used in medicine such as tincture iodine, cough syrup and many tonics.
- Identify the compound ‘Y’.
- How will you convert to ethene? Give reaction involved.
(b) People use a variety of method to wash clothes; usually after adding the soap, they ‘beat’; the clothes on a stone of beat it with a paddle, scrub with a brush of the mixture is agitated in a washing machine.
Why is agitation necessary to get clean clothes?
(c) Represent the formation of micelles with a well-labeled diagram.
(d) Give two difference between soap and detergent. (5)
Or
- Write various steps used in nomenclature of organic compounds.
- Describe versatile nature of carbon.
- Give electron dot representation of benzene. What type of hydrocarbon it is.
Section – B
Q 17. Give an advantage of solar cell over windmill. (1)
Q 18. Name the type of reproduction in Leishmania. (1)
Q 19. When we eat something we like, our mouth ‘Waters’. What is the actual meaning of this statement? (1)
Q 20. (a) What is advantage of taking in of water by fish through their mouth and forcing it past the gills?
(b) Compare the intestinal length of herbivores and carnivores. (2)
Q 21. Give three common features in lungs & gills. (2)
Q 22. Give the function of thymus gland and pineal gland. (2)
Q 23. (a) What do you mean by Coliform?
(b) Why there is need to clean aquarium time to time. (2)
Q 24. Three friends went for fishing to a pond. The nearby farms have fresh, greenish, insect free peas. Will you suggest them to sit there or to go elsewhere? Support your answer with suitable reason. (2)
Q 25. Give principle of
(i) Solar cell
(ii) Wind mill
(iii) Geothermal energy. (3)
Q 26. Give two limitation of nerve impulse. How can our body over come this? (3)
Q 27. Answer the following by giving reason:
- Fossil furnishes the direct and most reliable evidence for evolution.
- All organisms have many common features.
- Tail of mice appears in next generation of it if its tail is cut down.
- Artificial selection is beneficial.
- The population of red beetles disappeared and green coloured beetles population increased in each generation in spite of presence of predator like crows?
Or
Draw diagram of female reproductive system in humans and mark the organs where fertilization and implantation takes place.
What happens if egg is not fertilized?
After fertilization, a tissue is formed called placenta; explain its structure and functions? (5)
Chemical reaction & equation
1. A colourless lead salt when heated produces a yellow residue and brown fumes.
- Name the lead salt.
- Name the brown fumes.
- Write balanced chemical equation for the following change. (3)
- What happens when a piece of iron metal is placed in copper sulphate solution? Write balanced chemical equation for the following change. (2)
- Give reasons for the following
- Bags of chips are flushed with nitrogen gas.
- Corrosion cause damage to metallic objects. (2)
- What is the relationship between oxidation and oxidizing agent in a redox reaction? Write an example of a redox reaction showing the relationship between oxidation and oxidizing agent. (2)
- What happens when following reaction takes place? Also write chemical equations and then balance them.
- Hydrogen gas combines with nitrogen gas
- Hydrogen sulphide burns in air
- Barium chloride solution reacts with aluminium sulphate solution.
- Potassium metal reacts with water
- Nitric acid reacts with slaked lime (5)
- Rahul put a substance A in the china dish and left it in the open air near the window. After some time its red colour changes to grey. Translate the above statement in a balanced chemical reaction. Also name the type of the reaction. (2)
- In a solution of sodium sulphate a colourless solution is added, which gives an insoluble substance and a soluble substance, sodium chloride. Write the reaction and identify the colourless solution and insoluble substance is formed. (1)
- How will you obtain an essential gas for photosynthesis from a calcium compound, which is used to manufacture the raw material for whitewashing? Write balanced chemical equation also. (1)
- Give two precautions, which you will take while performing the decomposition of ferrous sulphate crystal. (2)
- Correct and balance
Ca + H2O CaOH (2)
- Give three differences between displacement and double displacement reaction. (3)
- Give one example of
- A combination reaction of an element and a compound.
- A double displacement reaction.
- A decomposition reaction of a compound into two or more compounds .(3)
13. How will you manufacture an organic compound CH4O having molecular mass 32 u with the use of lightest known element. Write balanced chemical equation also.
(2)
Acid, Bases & Salts
MM: 30
Q 1. Why gas is to be passed through a guard tube during humid climatic conditions? (1)
Q 2. Name the acid present in sour milk or curd. (1)
Q 3. Three solutions A, B and C have pH 2, 4 and 6 respectively. Which of the three solutions has maximum acid strength? (1)
Q 4. What happens when?( also write equation)
- CO2 is passed through limewater in limit.
- CO2 is passed through limewater in excess. (2)
Q 5. What is the difference between a base and an alkali? (1)
Q 6. Ammonia is also considered as a base although it does not contain hydroxyl ion. Why? (1)
Q 7. What is chlor-alkali process? Why is it called so? (2)
Q 8. A white powder having an odour of chlorine is used to remove yellowness of white clothes. Name this powder. How is it prepared? Write the chemical equation for the reaction involved in its preparation. (2)
Q 9. State whether washing soda crystal is acidic or alkaline. (1)
Q 10. Name the compound, which is used in hospitals for setting fractured bones. How is it prepared? Give important uses of plaster of Paris. (2)
Q 11. You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube? (2)
Q 12. Why should curd and sour substances not be kept in brass and copper vessels? (1)
Q 13. Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride. (2)
Q 14. Why do HCl, HNO3, etc., show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character? (1)
Q 15. Why does dry HCl gas not change the colour of the dry litmus paper? (1)
Q 16. While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid? (1)
Q 17. A milkman adds a very small amount of baking soda to fresh milk
(a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
(b)Why does this milk take a long time to set as curd? (2)
Q 18. Plaster of Paris should be stored in a moisture-proof container. Explain why? (1)
Q20. A first aid manual suggests that vinegar should be used to treat wasp stings and baking soda for bee stings.
- What does this information tell you about the chemical nature of the wasp stings?
- If there were no baking soda in the house, what other household substance could you use to treat bee stings?(2)
Q21. A road tanker carrying an acid was involved in an accident and its contents spilled on the road. At the side of the road, iron drain covers began melting and fizzing as the acid ran over them. A specialist was called to see if the acid actually leaked into the near by river.
(a) Explain how the specialist could carry out a simple test to see if the river water contains some acid or not.
(b) The word ‘melting’ is incorrectly used in the report. Suggest a better name that should have been used for the same purpose.
(c) Explain why the drain covers began fizzing as the acid ran over them. (3)
Normal Test-Light
MM: 20
1. A square wire of side 3cm is placed 25 cm away from a concave mirror of focal length 10 cm, what is the area enclosed by the image of the wire? (The center of the square lies on the principal axis and is perpendicular to the axis.) (3)
2. An object is placed 20 cm in front of mirror is found to have an image 15 cm (a) in front (b) behind the mirror. Find focal length of mirror and kind of mirror in each case. (3)
3. What is snell’s law of refraction? Give a condition when it fails. (2)
4. A concave mirror of focal length produced a real image n times the size of the object. Find the object distance?
(2)
5. A mirror forms 2 times real and inverted image when object is placed at distance of 18 cm. At what distance object should be placed so that image is 3 times virtual erect. (3)
6. An object 50 cm tall is placed on the principal axis of a lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm. from the lens. Calculate the focal length of the lens. Draw ray diagram also.(3)
7. Place a large shallow bowl on a table and put a coin in it and move away slowly from the bowl and stop when the coin just disappears from your sight. Then you ask a friend to pour water gently into the bowl without disturbing the coin. Keep looking for the coin from your position. Does the coin become visible again from your position? How could this happen. (2)
8. A pond appears to be shallower than it really is when viewed obliquely. (2)
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Normal Test-Light
1. A square wire of side 3cm is placed 22 cm away from a concave mirror of focal length 10 cm, what is the area enclosed by the image of the wire? (The center of the square lies on the principal axis and is perpendicular to the axis.) (3)
2. An object is placed 20 cm in front of mirror is found to have an image 16 cm (a) in front (b) behind the mirror. Find focal length of mirror and kind of mirror in each case. (3)
3. What are the advantages and disadvantages of using a convex mirror for seeing traffic at the rear?( one each) (2)
4. A concave mirror of focal length produced a real image n times the size of the object. Find the object distance?
(2)
5. A mirror forms 2 times real and inverted image when object is placed at distance of 18 cm. At what distance object should be placed so that image is 3 times virtual erect. (3)
6. An object 15 cm tall is placed on the principal axis of a lens. Its 7 cm tall image is formed on the screen placed at a distance of 10 cm. from the lens. Calculate the focal length of the lens. Draw ray diagram also. (3)
7. Place a large shallow bowl on a table and put a coin in it and move away slowly from the bowl and stop when the coin just disappears from your sight. Then you ask a friend to pour water gently into the bowl without disturbing the coin. Keep looking for the coin from your position. Does the coin become visible again from your position? How could this happen. (2)
8. A pond appears to be shallower than it really is when viewed obliquely. (2)
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