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Questions of this subject!.
| 1)Write the number of covalent bonds in the molecule of ethane. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 2)Name the life process of an organism that helps in the growth of its population. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 3)What will be the amount of energy available to the organisms of the 2 nd trophic level of a food chain if the energy available at the first trophic level is 10,000 joules? CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 4)The absolute refractive indices of glass and water are 4/3 and 3/2 , respectively. If the speed of light in glass is 2 × 10 8 m/s, calculate the speed of light in. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 5)List two main causes of the pollution of water of the river Ganga . State how pollution and contamination of river water prove harmful for the health of the people of neighbouring areas. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 6)What is biodiversity? What will happen if biodiversity of an area is not preserved? Mention one effect of it. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 7)List two tests for experimentally distinguishing between an alcohol and a carboxylic acid and describe how these tests are performed. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 8)Draw the electron - dot structure for ethyne. A mixture of ethyne and oxygen is burnt for welding. In your opinion, why cannot we use a mix ture of ethyne and air for this purpose? CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 9)Two elements ‘P’ and ‘Q’ belong to the same period of the modern periodic table and are in Group 1 and Group 2 , respectively. Compare their following characteristics in tabular form: CBSE- class10- Science 2015 | 1 | 0 | 1 |
| 10)List six specific characteristics of sexual reproduction. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 11)Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the modern periodic table and how valency of an element is calculated on | 0 | 0 | 1 |
| 12)What are chromosomes? Explain how in sexually reproducing organisms the number of chromosomes in the progeny is maintained. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 13)List four points of significance of reproductive health in a society. Name any two areas related to the reproductive health which have improved over the past 50 years in our country. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 14)Explain with an example for each, how the following provides evidences in favour of evolution in organisms: CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 15)Explain the following: (a) Speciation (b) Natural Selection CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 16)If the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a ray diagram to justify your answer. Where and why do we general | 0 | 0 | 1 |
| 17)What is meant by scattering of light? Use this phenomenon to explain why the clear sky appears blue or the Sun appears reddish at sunrise. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 18)Differentiate between biodegradable and non - biodegradable substances with the help of one example each. List two changes in habit that people must adopt to dispose non - biodegradable waste, for saving the environment. CBSE- class10- Sci | 0 | 0 | 1 |
| 19)Both soap and detergent are some type of salts. What is the difference between them? Describe in brief the cleansing action of soap . Why do soaps not form lather in hard water? List two problems that arise due to the u | 0 | 0 | 1 |
| 20)(a) Name the human male reproductive organ that produces sperms and also secretes a hormone. Write the functions of the secreted hormone. (b) N ame the parts of the human female reproductive system where. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 21)How do Mendel’s experiments show that the. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 22)What is meant by power of a lens? Define its SI unit. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 23)What is meant by power of a lens? Define its SI unit. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 24)What do we observe on pouring acetic acid on red and blue litmus papers? CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 25). While preparing soap a small quantity of common salt is generally added to the r e action mixture of vegetable oil and sodium hydroxide. Which one of the following may be the purpose of adding common salt? CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 26)A student was asked to observe and identify the various parts of an embryo of a red kidney bean seed. He identified the parts and listed them as under: CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 27)Given below is the list of vegetables available in the market. Select from these the two vegetables having homologous structures: CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 28)A student obtains a sharp image of the distant window (W) of the school laboratory on the screen ( S ) using the given concave mirror (M) to determine its focal length. Which of the following distances should he measure to get the focal | 0 | 0 | 1 |
| 29)A student used a device (X) to obtain/focus the image of a well illuminated distant building on a screen ( S ) as shown below in the diagram. Select the correct statement about the device (X). CBSE- class10- Science 2015 | 1 | 0 | 1 |
| 30)A student traces the path of a ray of light through a triangular glass prism for different values of angle of incidence. On analyzing the ray diagrams, which one of the following conclusions is he likely to draw? CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 31)Students were asked to observe the permanent slides showing different stages of budding in yeast under high power of a microscope. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 32)When you add sodium hydrogen carbonate to acetic acid in a test tube, a gas liberates immediately with brisk effervescence. Name this gas. Describe the method of testing this gas. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 33)Write the number of covalent bonds in the molecule of propane, C3H8 . CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 34)Where is DNA found in a cell? CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 35)The first trophic level in a food chain is always a green plant. Why? CBSE- class10- Science 2015 | 0 | 0 | 2 |
| 36)The absolute refractive indices of glass and water are 4/3 and 3/2 , respectively. If the speed of light in glass is 2 × 10 8 m/s, calculate the speed of light in. CBSE- class10- Science 2015 | 0 | 0 | 1 |
| 37)We often observe domestic waste decomposing in the bylanes of our homes. List four ways to make the residents aware that improper disposal of wastes is harmful to the environment and also for their own health. CBSE- class | 0 | 0 | 1 |