FIITJEE SUBJECT: SCIENCE (CBSE) CLASS 10 SOLUTION SECTION A

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FIITJEE SUBJECT: SCIENCE (CBSE) CLASS 0 SOLUTION. The other two points are M and C. SECTION A. Refer to the NCERT Book. 3. (i) By applying grease and paints on the iron articles.

1 FIITJEE SUBJECT: SCIENCE (CBSE) CLASS 0 SOLUTION. The other two points are M and C. SECTION A. Refer to the NCERT Book. 3. (i) By applying grease and paints on the iron articles. (ii) By coating of zinc layer over the iron articles by Galvanisation process. 4. (i) Light speeds up as it travels from a denser medium to a rare one, i:e, from a medium with a higher refractive index to one with a lower refractive index. An example would be the medium pair of diamond and water, where light travels from diamond to water. (ii) Using the same argument, light slows down as it travels from a medium with a lower refractive index to one with a higher refractive index. Therefore the medium pair of crown glass and ruby can be taken as an example, where light moves from the crown glass to the ruby. 5. Refer to the NCERT Book. 6. The pattern of magnetic field lines of a current carrying solenoid is given below: The field lines are parallel to the axis of solenoid inside. This unplies the magnetic field is uniform at all points inside the solenoid. An electromagnet is an application of magnetic field of current carrying solenoid. 7. The student is suffering from myopia or near sightedness (i) When the student is seated a the last desk the image of the black board. Writing is formed in front of the retina. The figure is shown below.

(ii) When the student is seated at the front desk, the image is formed at the retina. This defect can be corrected by using concave lens of desired focal length. 8. Metals.

2 (ii) When the student is seated at the front desk, the image is formed at the retina. This defect can be corrected by using concave lens of desired focal length. 8. Metals. Metals form basic oxide with oxygen of air.. Metals can displace hydrogen from dilute acids. 3. Metals show displacement reactions on the basis of their reactivity series. Non-metals. Non-metals form acidic oxides with oxygen of air.. Non-metals cannot displace hydrogen from dilute acids. 3. Non-metals do not show such displacement reaction. 9. Structural formula of ethanol: C C O On heating ethanol with conc. SO 4 acid ethane gas is produced. Conc. SO 3 443K 4 4 C C O C O Ethanol Ethene Conc. SO 4 acid acts as dehydrating agent which absorbs the released water. 0. Refer to the NCERT Book.. Refer to the NCERT Book.. (a) The first lens is of power +D. ence it has a focal length equal to.

3 f 0.5m f ence first lens is a concave lens of focal length 0.5m. The second lens is of power -4D. ence, it has a focal length equal to f 0.5m f 4 (b) It is given that, u = -00cm = -m. For first lens f v u v f u 0.5 v m 00cm Magnification is v m u For second lens: f v u 5 v f u 0.5 v m.m 0cm 5 v 0 m 0.0 u 3. (a) Aluminium (Al) metal has highest valency of 3. As it has 3 valence electrons in its outermost shell. (b) Na atoms have largest atomic radius. As the atomic radius of atoms of the elements of same period go on decreasing as we move from left to right in a period. (c) Na metals will show maximum chemical reactivity, as chemical reactivity among the metals goes on decreasing in the same period as we move from left to right in that period. 4. Refer to the NCERT Book. 5. Refer to the NCERT Book. 6. Appliances are connected in parallel to one another in domestic circuits due to the following reasons. (i) When connected in parallel, appliances can be operated independently. The operation of each appliances not dependent on the other. Switching off any appliance will not affect the working of other appliance. (ii) Each appliance gets same constant voltage. Numerical: Given, Electric fuse rating = 5A

4 Power of heater =.5kw Voltage = 0V The safe current drawn by the electrical heater is given by: P.5kw 500w i 6.8A V 0V 0V The fuse will not blow off even if the current in the heater will exceed its safe current values. This may damage the appliances and even cause firing. Any fuse of lower ampere range needs to be put in the circuit. 7. (a) (i) Living organisms can survive only in a narrow range of p change. Acidic rain water when flows into the rivers, it lowers the p value of river water and makes the survival of acquatic life in such river water difficult. Plants require a specific p range for their healthy growth. (ii) Our stomach and intestines work in a specific p range. Stomach acts in slightly acidic medium while small intestine digests the food in slightly alkaline medium. (iii) Tooth decay starts when the p of the mouth is lower than 5.5. (b) When electricity is passed through an aqueous solution of sodium chloride (called brine), it decomposes to form sodium hydroxide. This process is called Chlor-alkali process because the products formed are chlorine and alkali NaO. NaCl(aq) O(l) NaO(aq) Cl (g) (g) Cl gas is given off at the anode and gas at the cathode while sodium hydroxide solution is formed near the cathode. 8. Refer to the NCERT Book. 9. (i) Graph I represents a direct current. Graph II represents an alternating current. (ii) A dry cell is a source of direct current. An a.c. generator is a source of alternating current. (iii) Time period of a.c. T = 0.05 Frequency of a.c. f 50z T 0.05 (iv) Direct current. () Both the magnitude and direction of current varies within equal interval of time. () Therefore frequency of a.c. is 50z or 60z depending upon the country. 0. ydrocarbons. As these compounds have only atoms of carbon and hydrogen elements in their molecules, so these are called ydrocarbons. General formulae: Alkanes C n n Alkenes C n n Alkynes C n n Structures of first member of each: Alkanes. Alkenes. Alkynes. C C C C C (Methane) (Ethene) (Ethyne) The reaction which converts Alkenes into Alkanes is called Addition Reaction.

5 Ni eat 3 3 C C C C Ethene Ni (Nickel) metal acts as catalyst in this reaction.. Refer to the NCERT Book. Ethane SECTION B. (a) With the help of a dropper one drop of the solution is placed on the stripe of the p paper. The colour developed on the p paper is compared with colour and the corresponding p value given on the chart of the p paper. (b). aqueous solution of sodium hydroxide is alkaline so its p will be more than 7.. dil Cl is acidic so its p value will be less than Chemicals needed for making of soap are - castor oil, alkaline, solution of sodium hydroxide and common salt. After the process of saponification, the product soap is tested with litmus paper. The soap solution turns red litmus to blue, showing that soap formed during this reaction is alkaline in nature. 4. Refer to the NCERT Book. 5. Refer to the NCERT Book. 6. (a) 0.5 Upper limit of class (b) least count 0.5 / V no.of divisions 7. Given I = 400 x 0-3 A =.4A V = 8V R = V/I =

KENDRIYA VIDYALAYA SANGATHAN, HYDERABAD REGION

KENDRIYA VIDYALAYA SANGATHAN, HYDERABAD REGION SAMPLE PAPER 01 F PERIODIC TEST III EXAM (2017-18) SUBJECT: SCIENCE (086) BLUE PRINT : CLASS X UNIT Chapter VSA (1 mark) SA I (2 marks) SA II (3 marks) LA