FIITJEE SUBJECT: SCIENCE (CBSE) CLASS 10 SOLUTION

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Claire Clark
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1 FIITJEE SUJECT: SCIENCE (CSE) CLSS 10 SOLUTION SECTION. Mechanical energy changes to electrical energy. 3. The Type of mirror is Convex. 4. X This is an alcohol. Y - This is an alkene. Z This is Hydrogen gas. Conc.H SO / 4 R CH CH OH R CH CH H O X Y Na/.RCH CH OH R CH CHONa H Z Role of H SO 4 :- It acts as dehydrating Reagent. 6. (a)(i) C D R CD R 4.5 CD R 13.5 D 13.5 D FIITJEE Ltd. Kanpur Centre 16/116 Karmin rcade (opp to ITO) Civil line, Kanpur. Mob ;

2 (ii) C RCD 6 RCD 18 (b) oth the bulbs one connected in parallel. Therefore, potential difference across each of them will be same that is 0V, current drawn by the bulb of rating 100W is given by. P / V 100 / Similarly, current drawn by the bulb of rating 60W is given by. P / V 60 / the total current drawn from the line = = Power of lens is the ability of the lens to converge the rays of light falling on it. The power of a lens is the reciprocal of its focal length in meters. It is represented by the letter P. The power P of a lens of local length f is given by f = 1/P. The S.I. unit of power is diopter. focallength 40cm P.5D f (m) 40 lensis convex focallenght 0cm P 5D lens is concave f 0 (m) D 10. (a) The formula for Resistance is given by. L R Its depends on the length, area and resistivity of the conductor, Resistivity varies for different conductors depending on the nature as of which they were made. Resistance of the conductor can also depend on other external factors like temperature. (b)metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity. (c) lloys are used rather than pure metals in electrical heating devices. Since they have also electrical conductivity and also a low melting point. 13. (a) Most of the carbon compounds are poor conductor of Electricity because all the valence electrons get involve in binding, there is no free electron which can carry current. FIITJEE Ltd. Kanpur Centre 16/116 Karmin rcade (opp to ITO) Civil line, Kanpur. Mob ;

3 (b) cyclo hexane Number of Single bounds = = Zn NaOH Na ZnO H Zn HCl ZnCl H The Hydrogen gas is evolved in both Reactions. Or The Salt used for this purpose is baking powder. It is mixture of Potassium Hydrogen tartarate & Sodium bicarbonate. Praparation of NaHCO 3 Nacl NH3 HOCO NaHCO 3 NH4Cl Two uses of NaHCO 3 s ntaacid. In Carbonation of soft drinks. 15. heat 3 electriccurrent Light CaCO (s) Cao(s) CO (g) H O(l) H (g) O (g) gcl(s) g(s) Cl (g) 16. (a) Student has myopic eye correction can be done by using concave lens. (b) Stare twinkle because they re so far away from earth that even through large telescope, they appear only as pinpoints and its easy for earth s atmosphere to disturb the pin point light of star. FIITJEE Ltd. Kanpur Centre 16/116 Karmin rcade (opp to ITO) Civil line, Kanpur. Mob ;

4 1. (a) left hand can be beheld, so as to represent three mutually orthogonal ones on the thumb, fore finger and middle finger. Each finger is thin assigned to a quantity (mechanical force, magnetic field and electric current) (b) It is based on fleming left hand rule. When a current carrying conductor is placed in a magnetic field. It experiences a mechanical force whose direction is given by fleming s Left hand rule and whose magnitude is given by. F = I L Newton. is the magnitude field in wb/m I is current is amperes. L is length of coil in meters. (c) rmature- rmature must carry current, so it is always a conductor or a conductive coil, oriented normal to both the field and to the direction of motion, torque (rotating machine). Or force (linear machine). rush rush is a device which conducts Current between stationary wires and many parts, most commonly is rotating shaft. Split ring- () To prevent this battery or power supply from shorting out. () To reverse the current in the rotor coil. When its magnetic moment is parallel to the magnetic field. (C) To prevent eddy currents from flowing 1. (a) Dobereiner Newland Mendeleev dvantage He did much to Stimulate new investigators to discover relationships between the Properties of the elements (Dobereiner s traids - 18) He gave the idea of Periodicity Ist time. He predicted the property of new element Limitation He couldn t all the elements in triads. The law was not applicable especially for the elements of higher atomic weights. Couldn t explain position of Hydrogen. (b) Henry Moseley (c) The physical and chemical properties of elements are a periodic function of their atomic numbers. FIITJEE Ltd. Kanpur Centre 16/116 Karmin rcade (opp to ITO) Civil line, Kanpur. Mob ;

5 SECTION 3. O F F 1 V F Principal focus Lens formula v u f v f u V 60cm v 60 m o u 30 Height of Image Height of object 4. V V Slope ohm I 5. while precipitate of aso 4 will be formed. Na SO 4(aq) acl (aq) aso 4(s) Nacl(aq) It is a double displacement reaction. 7. Exp. No.-1 l 3FeSO l (SO ) 3Fe l 3CuSO 4 l (SO 4) 3 3Cu Exp. No.- Fe l (SO ) NoReaction 4 3 Fe CuSO 4 FeSO 4 Cu Test tubes, & D show change in colour, due to displacement reactions. luminium is most reactive metal because its standard reduction potential is less than other or it is senior metal in activity series. FIITJEE Ltd. Kanpur Centre 16/116 Karmin rcade (opp to ITO) Civil line, Kanpur. Mob ;

Sub- Science (Physics and Chemistry ) Important questions for board purpose

Class -10 Sub- Science (Physics and Chemistry ) Important questions for board purpose Note: Students are requested to solve these questions in separate notebook/a-4 sheets. 1. Burning of fossil fuels result