The following question are taken from the last year’s final exam of HSLC which is conducted by SEBA board of Assam, 2018. These are the General Science question 2018 .Soon.. We will provide answers of these questions. It is very necessary for a HSLC candidate to know about that how he have to prepare. And also necessary to know what is the pattern of final questions. So we are providing the Previous Year questions in a easy and suitable manner so that one can understand easily, Read easily and the most important feature is one can get every where and any time whenever you need. We are trying to provide more previous years questions like 2017,16,15 etc. We are trying our label best. Our answer are written by some expert teachers.
General Science Previous Year Questions- 2018
GROUP – A
For each question given below, four answers are given. Out of four only one answer is correet. Select the correct answer
1. Fe203 + 2Al —> Al203 + 2Pe The above reaction is an example of a
(a) combination reaction
(b) double displacement reaction
(c) decomposition reaction
(d) displacement reaction
2. Food cans are coated with tin and not with zine because
(a) zine is costlier than tin
(b) zinc has a higher melting point than tin
(c) zinc is more reactive than tin
(d) zinc is less reactive than tín
3. A solution turns red litmus blue. Its pH is likely to be
4. Which of the folkowing is not a correct statement about the trends when going from left to right across the periods of the trends when going Periodic Table?
(a) The elements become less metallic in nature.
(b) The number of valence electrons increases.
(c) The stoms lose their valence electrons more easily.
(d) The oxides become more acidic.
5. The name of the process with the help of which carbon and energy requirements of an autotrophic organism are fulfilled, is
6. The hormone produced by the pancreas that helps in regulating the blood sugar level is
7. The part of the brain responsible for the sensation of hunger and thirst is
8. An electric bulb is rated 220 V and 100 w. When it is operated on 110 V, then the power consumed is
(a) 75 w
(b) 25 W
(c) 100 w
(d) 50 w
9. Which of the following is not derived from energy of the sun?
(b) Nuclear energy
(c) Geothermal energy
(d) Wind energy
GROUP – B
10. Which of the following groups contains only biodegradable items?
(a) Cake, wood and grass (b) Fruit peels, cake and lime juice
(c) Grass, wood and plastic
(d) Grass, flower and leather
11. What is the common name of the compound CaOCl2?
12. Why is the conversion of ethanol to ethanoic acid an oxidation reaction?
13. What is cross-pollination?
14. In which type of reproduction, exchange of genetical material takes place?
15. Define the unit of current.
16. Translate the following statements into chemical equations and then balance therm
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
17. What does one mean by exothermic and endothermic reactions? Give examples.
(a) Why do we apply paint on iron articles?
(b) Oil and fat containing food items are flushed with nitrogen. Why?
18. What is the chemical name of baking soda? How is it produced? Give chemical equation.
19. Mention the factors that could lead to the rise of a new species.
20. Why is a normal eye not able to see clearly the objects placed closer than 25 cm?
21. Light enters from air to glass having refractive index 1.5 . What is the speed of light in the glass? (Speed of light in vacuum is 3×108 ms-1 )
22. State the basic principle of an electric motor. What is the function of a split ring in an electric motor?
23. Write two precautions taken to avoid the overloading of domestic electric circuits.
24. Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which one of these will be more electronegative? Why?
(a) Besides gallium, which other elements have since been discovered those were left by Mendeleev in his Periodic Table? (Any hwo)
(b) Use Mendeleev’s Periodic Table to predict the formulac for oxides of the following elements K and Al
c) Why do you think the noble gases are placed in a separate group?
25. How does nerve impulse travel in our body?
26. What is the process of reproduction in amoeba? What are the advantages of sexual reproduction over asexual reproduction?
27. What is a dominant character? How did Mendel prove through his experiments that the inherited characters are transmitted independently from one generation to the next?
Define homologous organs and analogous organs. Can the wings of a bird and that of a bat be considered as homologous organs? Justify your answer
28. The far point of a myopic person is 80 cm in front of the eye What is the nature and power of the lens required to correct the problem? Why do we have two eyes for vision and not just one?
What are the defects of vision? A person needs a lens of power -5:5 dioptres for correcting his distant vision. For correcting his near vision, he needs a lens of power +1.5 dioptres. What is the focal length of the lens required for correcting distant vision?
29. State Joule’s law of heating. When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit, Find the value of the resistance of the resistor.
What is the commercial unit of electrical energy? which uses more energy-a 280 W TV set in 1 hour or a 1200 w ciecttie iron in 10 minutes and how?
30. Why are we looking at alternative sources of energy? Name a non-conventional source of energy and its two advantages.
31. what is the role of decomposers in the ecosystem? Draw a diagram showing flow of energy in an ecosystem.
32. (a) what happens when ethanol is heated with alkaline KMn04 or acidified K2Cr207? Write the chemical equation for the reaction.
(b) Explain substitution reaction with one example.
(c) Write the names of the following compounds :
(a) what are the products formed when ethanoic acid reacts with sodium carbonate? Write the chemical equation for the reaction.
(b) Explain the mechanism of the cleaning action of soaps.
(c) Draw the structure of butanone.
33. (a) What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.
(b) Give reasons
(i) Platinum, gold and silver are used to make jewellery
(ii) Sodium, potassium and lithium are stored under oil.
(iii) Aluminium is a highly reactive metal, Yet it is used to make utensils for cooking.
(a) What is refining of metals? Mention the most widely used method for refining of impure metals, What is anode mud?
(b) Explain, why :
(i) silver articles become black after some time when exposed to air.
(ii) Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat.
34. Name the parts of the excretory system in humans. Describe the mechanism of urine formation and elimination.
What are the components of the transport system in highly organized plants? How are water and minerals transported in plants? What is the role of transpiration in transporting water and minerals in plants?
35. Draw the ray diagram of image formation by a convex mirror when the object is placed at its centre of curvature (C). 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
A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object?
Also, find the power of the lens.
Find the power of a concave lens of focal length 2 m.
36. what forces would be working against an equitable distribution of our resources? Suggest some approaches towards the conservation of forests.
What is the importance of reduce, recycle and reuse to save the environment? What changes can you make in your habits to become more environment-friendly?