Activity Booklet Science 10th 2023 PDF

 Ch-1: Chemical Reactions & Equations Burning of a magnesium ribbon in air and collection of magnesium oxide in a watch-glass Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Chalo Clean it wit...

 Ch-1: Chemical Reactions & Equations Burning of a magnesium ribbon in air and collection of magnesium oxide in a watch-glass Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Chalo Clean it with sandAb Ise AASAN BHASHA MEI Samajhte hai : paper. Hold the magnesium ribbon with Take about 2 cm a pair longofmagnesium tongs , and start heating. its other end. ribbon The Magnesium Ribbon starts burning. Clean it with sand paper. BUT IT'S NOT BURNING ALONE. HoldIt the startsmagnesium burning with a ribbon with a pair WHITE DAZZLING of.tongs , and start heating its FLAME other And now to collect the Magnesium Oxide end.hold it over a Watch Glass Powder The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass Q: Why Magnesium ribbon is cleaned before burning in the air ? Ans: The magnesium ribbon which we use usually has a coating of ‘magnesium oxide’ on its surface which is formed by the slow action of oxygen of air on it. So, before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper. This is done to remove the protective layer of magnesium oxide from the surface of magnesium ribbon so that it may readily combine with the oxygen of air (on heating). Q: Why the magnesium ribbon should be burned by keeping it as far as possible from the eyes? Ans: The dazzling (very bright) white light given out during the burning of magnesium ribbon is harmful to the eyes. So, the magnesium ribbon should be burned by keeping it as far as possible from the eyes. " 10th मतलब ?? - Shobhit Nirwan "  Formation of Precipitate Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : (i) Take some lead nitrate solution in a test-tube (or a beaker). (ii) Add potassium iodide solution to it. (iii) A yellow precipitate of lead iodide is formed at once. (iv) A change in colour (from colourless to yellow) also takes place in this chemical reaction. Chemical Reactions that evolve Gases AND RIse In Temperature Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : (Take some Zinc Granules in a Conical Flask Now on Adding the Sulphuric Acid you will See a Magic. As You will see the bubbles of HYDROGEN GAS forming around the zinc metal We verified that it is Hydrogen gas because its bubbles burnt with pop sound when passed through soap solution (As shown below diagram) Also, if we will touch the flask with our hands we will see that it is too HOT. So we get to know that along with evolution of gas temperature also rises in the Chemical Reactions. " 10th मतलब ?? - Shobhit Nirwan "  Decomposition reaction of ferrous sulphate. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 grams of Ferrous Sulphate Crystals in a DRY Boiling Tube. They are originally Green In Colour Heat the boiling tube over a burner Now You will again see the magic. As the green colour first changes to White And then Finally a Brown Solid is formed(which is ferric oxide) So the main observation of this activity is that the smell of burning Sulphur comes out along with the colour change from Green to White and then Brown. Decomposition reaction of lead nitrate Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 grams of lead nitrate powder in a boiling tube. Lead nitrate is a colourless compound. Hold the boiling tube in a test-tube holder and heat it over a burner. Brown fumes of nitrogen dioxide gas are evolved which fill the boiling tube. If a glowing splinter is held over the mouth of the boiling tube, it catches fire and starts burning again. This shows that oxygen gas is also evolved during this reaction. A yellow solid is left behind in the boiling tube. This is lead monoxide (Please note that lead monoxide is reddish-brown when hot but yellow when cold). " 10th मतलब ?? - Shobhit Nirwan "  Decomposition of silver chloride is caused by light Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 grams of silver chloride in a china dish. It is white in colour. Place this china dish in sunlight for some time. We will find that white silver chloride turns greyish white (due to the formation of silver metal). Silver bromide also behaves in the same way as silver chloride with light energy. Displacement reaction between iron (nail) and copper sulphate solution. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 10 mL of copper Sulphate solution in a test tube. Its original colour is Deep Blue Now take a big iron nail and clean it same like u did with Magnesium Ribbon using the sand paper. Now put the iron nail in the solution and then see the magic. After sometime like half an hour we will see that the iron nail would be covered with red-brown layer. And this layer would be of our another metal that is Copper. So Finally we will see that the original Deep blue colour has faded and the solution turns to light Green Colour. " 10th मतलब ?? - Shobhit Nirwan " Double displacement reaction between barium chloride and sodium sulphate. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take 3mL of Sodium Sulphate solution in a test tube. And take 3mL of Barium Chloride but in another test tube. Add Barium Chloride solution to Sodium Sulphate solution And the magic we see is now of White colour as a White Precipitate is left over in the Test Tube. Oxidation of copper to copper oxide Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 1 gram of copper powder in a china dish. It is redbrown in colour. Heat the china dish strongly over a burner (see Figure 55). A black substance is formed. This black substance is copper oxide " 10th मतलब ?? - Shobhit Nirwan "  Ch-2: Acids, Bases and Salts Reaction of zinc granules with dilute sulphuric acid and testing hydrogen gas by burning Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN other end. BHASHA MEI Samajhte hai : Take a few piecesTheofMagnesium zinc granulesRibbon starts in a boiling tubeburning. and add about 5 mL of dilute sulphuric acidBUTto itIT'S. NOT BURNING ALONE. We will observe It startstheburning formation of gas with bubblesDAZZLING a WHITE on the surface of zinc. granules. FLAME Pass Andthe now gastobeing formed collect thethrough the soap Magnesium solution Oxide taken inhold Powder a trough (by a it over means of a glass delivery tube). Gas filled bubbles are formed in the soap Watch Glass solution which rise into the air. Bring a burning candle near a gas-filled soap bubble. The gas present in soap bubble burns with a ‘pop’ sound (making a little explosion). Only hydrogen gas burns making a ‘pop’ sound. This shows that hydrogen gas is evolved in the reaction of dilute sulphuric acid with zinc metal (taken in the form of zinc granules) TEST for CO2 gas Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take a boiling tube and put about 0.5 g of sodium carbonate in it. Add aboutChalo 2 mLAbof Ise AASAN dilute BHASHA hydrochloric acid inMEI Samajhte the boiling hai : a tube (through Take about 2 cm long magnesium ribbon. thistle funnel) Clean We will observe that brisk it with sand effervescence of a paper. gas is produced. HoldPass the the magnesium gas throughribbon with lime water. Thea lime pairwater of tongs , and(showing turns milky start heating that it is its carbon dioxide gas). other end. Keep on passingThe Magnesiumgas carbon dioxide through Ribbon milky lime starts water for some more burning. time. The lime water becomes clear again. BUT IT'S NOT BURNING ALONE. This shows that the white precipitate of calcium carbonate dissolves on passing It starts burning with a WHITE DAZZLING FLAME. excess of carbon dioxide gas. We can repeat this experiment by using sodium And now to collect hydrogencarbonate the in place ofMagnesium Oxide sodium carbonate. Powder Again we willhold it over a get carbon dioxide gas which will turn lime waterWatchmilky.Glass On passing excess of carbon dioxide, the milky lime water will become clear again. Activity to investigate whether all compounds containing hydrogen are acidic. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Chalo Take Ab Ise 2AASAN about BHASHA cm long MEI Samajhte magnesium hai :. ribbon (i) Take solutions of hydrochloric acid, sulphuric acid, glucose and alcohol. All Clean it with sand paper. these are hydrogen containing compounds. Hold the magnesium ribbon with a pair of tongs , and start heating its (ii) Fix two iron nails on a rubber cork and place the cork in a beaker.(Fig (a) on next page) other end. Theto (iii) Connect the nails Magnesium Ribbon the two terminals starts of a 6 burning. volt battery through a switch and a bulb. BUT IT'S NOT BURNING ALONE. It starts (iv) Pour some dilute burning hydrochloricwith acidasolution WHITE(HClDAZZLING solution) inFLAME. and the beaker Andon switch now the to collect current. The the bulb Magnesium Oxide starts glowing.(Fig a) Powder hold it over a This shows that hydrochloric acid solution Watch taken Glassin the beaker conducts electricity. If we repeat this experiment by taking sulphuric acid solution in the beaker, the bulb glows again. This shows that sulphuric acid solution also conducts electricity. In fact, all the acid solutions conduct electricity. (v) Let us now take glucose solution (C6H12O6 solution) in the beaker and switch on the current. The bulb does not glow in this case (Fig b). This shows that glucose solution does not conduct electricity. If we repeat this experiment by taking alcohol solution in the beaker, the bulb does not glow again. This shows that alcohol solution also does not conduct electricity. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass Experiment to show that acids do not show acidic behaviour without water. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN other end.MEI Samajhte hai : BHASHA Take about 1 g The SolidMagnesium sodium chloride Ribbon (NaCl) instarts burning. clean and dry boiling tube and add conc. sulphuric acid BUT to it IT'S NOTand carefully BURNING ALONE. fit the rubber con over glass tube. It starts Conc. sulphuric acidburning with reacts with a WHITE Sodium DAZZLING chloride FLAMEchloride to form hydrogen. gas. The hydrogen And now to chloride collectgasthestarts coming outOxide Magnesium of the open Powderenclave. hold it over a Hold a 'dry' blue litmus paper in HCl gas. So there is no change in the colour of dry Watch Glass blue litmus paper. This show shows that HCl gas does not behave as an acid to the absence of water. We now hold a 'moist' blue litmus paper in HCl gas, Now we will see the 'moist' blue litmus paper to red. This shows that HCl gas show acidic behaviour in the presence of water. Conclusion: HCl gas does not shout acidic behaviour in absence of water but it shows acidic behaviour in presence of water. " 10th मतलब ?? - Shobhit Nirwan "  Adding Acid/Base in Water Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. Chalo It starts Ab Ise AASAN burning with aBHASHA WHITEMEI Samajhte hai DAZZLING : FLAME. The process of dissolving an acid or a base in water is a highly exothermic one. And now to collect the Magnesium Oxide Powder hold it over a Ans- Watch Glass i. Yes beaker becomes hot on adding H2SO4 (Acid) ii. Exothermic reaction took place. Determining Family of Salts Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Chalo AbClean it with Ise AASAN sandMEI BHASHA paper. Samajhte hai : Hold Ans-the (i. &magnesium ribbon ii.) Formulas and with a pair of tongs , and start heating its identification- other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass iii. Na2SO4, NaCI, NaNO3 and Na2CO3 belong to the family of sodium salts. K2SO4, Na2SO4, CaSO4, MgSO4, CuSO4 belong to the family of sulphate salts. NaCI and KCI belong to the family of chloride salts. " 10th मतलब ?? - Shobhit Nirwan "  pH, Acids and Bases Used Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The ChaloMagnesium Ab Ise AASANRibbon BHASHA starts burning. MEI Samajhte hai : Ans- BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass Are the Crystals of Salts really Dry? Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. Chalo Ab Ise AASAN Ribbon The Magnesium BHASHA MEI Samajhte starts hai : burning. i) Take a tube, add few crystals of copper sulphate and heat it. BUT IT'S NOT BURNING ALONE. ii) On heating copper sulphate will start appearing white. It starts burning with a WHITE DAZZLING FLAME. iii) Copper sulphate crystals contain water of crystallisation. When heated the And now crystals, to collect this water theand is removed Magnesium the salt turnsOxide white.Powder hold it over a iv) On adding 2-3 droplets of water,Watch Copper Glass sulphate crystals restore its blue colour. " 10th मतलब ?? - Shobhit Nirwan "  Ch-3: Metals and Non-Metals Chalo Ab Metals, in Ise AASAN their BHASHA pure state, MEI have Samajhte a shining hai : surface. Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : BUT IT'S NOT BURNING ALONE. Metals, in their pure state, have a shining surface. It starts burning with a WHITE DAZZLING FLAME. So, before rubbing and cleaning with sample paper, metals had less shiny surface. And After now to rubbing andcollect cleaningthe withMagnesium Oxide sand paper, they'll Powder become morehold shiny.it over a Watch Glass Metals are *generally* hard Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : BUT IT'S NOT BURNING ALONE. i. Metals like iron, copper, aluminium and magnesium are hard to cut with knife. It starts ii. Hold a piece burning of sodium metalwith a pair with a WHITE DAZZLING of tongs, put on a FLAME. We watch-glass. And now observe it cantobecollect cut easilythe withMagnesium a knife. Oxide Powder hold it over a Watch hard. iii. We observed that metals are generally GlassThe hardness varies from metal to metal. Chalo Some Abmetals Ise AASAN BHASHA can be beatenMEIintoSamajhte thin sheets hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Chalo Ab Ise AASANRibbon BHASHA MEIstarts burning. Samajhte hai : We observed that some BUT IT'Scan metals NOTbe BURNING ALONE. beaten into thin sheets. This property is It starts burning with a WHITE DAZZLING FLAME. called malleability. Gold And now toare and silver the most collect themalleable metals Oxide Powder hold it over a Magnesium Watch Glass " 10th मतलब ?? - Shobhit Nirwan "  Metals are good conductors of heat and have high melting points Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Chalo Ab Ise AASANRibbon starts BHASHA MEI burning. Samajhte hai : BUT IT'S NOT BURNING ALONE. i. On heating the wire we'll find that the heat from burner will travel in the whole It starts wire melting the wax.burning with a WHITE DAZZLING FLAME. ii. And now to On melting, pincollect the will drop. ButMagnesium Oxide metal wire doesn't Powder melt becausehold of highit melting over a point of metals. Watch Glass iii. We observed that metals are good conductors of heat and have high melting points Chalo AbMetals Ise AASANalso BHASHA MEI Samajhte hai : conduct electricity Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : i. On placing the metalBUT IT'S in the NOTbetween circuit BURNING ALONE. terminals A and B, we find that the bulb glows. It starts burning with a WHITE DAZZLING FLAME. ii. And now that This shows to collect thegood metals are Magnesium Oxide conductor of Powder electricity too. hold it over a Watch Glass Most non-metals produce acidic oxides when dissolve in water Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : i. Take a magnesium ribbon and some sulphur powder, Burn the magnesium ribbon: Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : 2Mg(s) + 02(g) -> 2MgO(s) Take about 2 cm long magnesium ribbon. ii. Collect the ashes formed and dissolve them in water.: Clean +itH20(I) MgO(S) with sand paper. -> Mg(OH)2(aq) Hold thethe iii. Testing magnesium ribbon resultant solution withwith botharedpair andof tongs blue litmus, and start paper, heating we find its it is Basic Mg(OH)2. other end. iV. Now burn sulphur The Magnesium powder. Ribbon Place a test starts tube over burning. the burning sulphur to collect the fumes produced: BUT IT'S NOT BURNING ALONE. S(s) + 02(g) -› SO2(g) It starts burning with a WHITE DAZZLING FLAME. v. Add some water to the above test tube and shake: And now to collect the Magnesium Oxide Powder hold it over a S02(g) + H20(1) - H2S03 (aq) vi. Testing this solution with blue andWatch Glass red litmus paper, it is acidic Sulphuric Acid, H2SO3. What happens when Metals are burnt in Air Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Chalo Ab Clean it with Ise AASAN sandMEI BHASHA paper. Samajhte hai : Hold thethe i. Collect magnesium ribbonmetals samples of following with a– pair of tongs aluminium, copper,, and iron,start lead, heating its magnesium, zinc and sodium. other end. ii. Hold samples with a pair The of tongs andRibbon Magnesium try burning over burning. starts a flame. eg- 2Mg(s) +BUT 02(g)IT'S -> 2MgO(s). --We'll getALONE. NOT BURNING metal oxide as product iii. Which metals burn easily- Sodium. It starts burning with a WHITE DAZZLING FLAME. iv. What flame colour did you observe when the metal burnt?- Yellow And now to collect the Magnesium Oxide Powder hold it over a v. How does the metal surface appear after burning?- Silver white Watch order vi. Arrange the metals in the decreasing Glassof their reactivity towards oxygen- Na > Mg > Al > Zn > Fe > Pb > Cu vii. Are the products soluble in water?- Sodium oxide is soluble in water. Other metal oxides are insoluble. viii. We have observed in Activity 3.9 that all metals do not react with oxygen at the same rate. Different metals show different reactivities towards oxygen " 10th मतलब ?? - Shobhit Nirwan "  Reaction of metals with Steam Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : A lump of glass wool soaked in water is placed at bottom of tube. The water in glassChalo Ab wool will Isesteam form AASAN BHASHA on heating. MEI Samajhte hai : The SampleTake about of metals 2 cm placed long in the magnesium middle ribbonkept of the horizontally. boiling tube. The boiling tube Clean it with containing sand water, soakedpaper. glass wool and metal sample Holdisthe magnesium arranged ribbon with a pair of tongs , and start heating its in apparatus. To start the experiment, the metal sample other end. is heated by using a burner when the metal getsThe hot,Magnesium then the glass Ribbon wool is heated startsbyburning. using other burner. The water present in glass wool forms steam on heating. This steam then BUT IT'S NOT BURNING ALONE. passes over the hot metal. The metal react with steam to form the metal oxide It starts burning with a WHITE DAZZLING FLAME. and H2 gas. And The nowH2 gastocome collect the out of theMagnesium boiling tube andOxide Powderover it is collected hold it over water whenaa lighted match stick is applied Watch Glass jar, the gas burns with a "pop" to gas collected sound, indicating that it is hydrogen. The metal oxide formed remains behind in the boiling tube. This experiment is performed by taking magnesium, aluminium, zinc and iron as metal sample. It is found that the reaction of steam with magnesium is most vigorous followed by reaction with aluminium and zine but reaction with iron is slowest. Magnesium is very reactive whereas the iron is least reactive. Decreasing order Mg › Al › Zn > Fe Metals like lead, silver and gold do not react with water or even steam. Only those metals displace hydrogen from water which are hydrogen in the reactivity series. " 10th मतलब ?? - Shobhit Nirwan "  What happens when Metals react with Acids? Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : i. Which metals reacted vigorously with dilute hydrochloric acid? Magnesium shows fastest reaction and hydrogen bubble formation. ii. With which metal did you record the highest temperature? Magnesium. iii. Arrange the metals in the decreasing order of reactivity with dilute acids. Mg > Al > Zn > Fe. How do Metals react with Solutions of other Metal Salts? Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : i. Put a clean copper wire and put it in a solution of iron sulphate. ii. Put a clean iron nail in a solution of copper sulphate. iii. After 20 minutes, it is observed that blue CuSO4 solution turns green. iv. In which test tube did you find that a reaction has occurred? -- Test tube containing CuSO4 solution. v. On what basis can you say that a reaction has actually taken place? -- The blue colour of CuSO starts fading. vi. Can you correlate your observations for the Activities 3.9, 3.10 and 3.11? -- Yes. In those activities, it is found that Iron is more reactive than copper. It displaces Cu from CuSO4 to form FeS04. vii. Write a balanced chemical equation for the reaction that has taken place. Fe(s) + CuSO4(aq) - FeSO4(aq) + Cu(s) viii.This is a displacement reaction. ie., reactive metals displace less reactive metals from their compounds in solution or molten form. " 10th मतलब ?? - Shobhit Nirwan "  CORROSION Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Observations after leaving them for a few days: i. The iron nails rust in test tube A, but they do not rust in test tubes B and C, because; ii. In test tube A, the nails are exposed to both air and water. iii. In test tube B, the nails are exposed to only water. iv. The nails in test tube C are exposed to dry air. v. This shows that both air and moisture are needed for rusting of iron. " 10th मतलब ?? - Shobhit Nirwan "  Ch-4: CARBON Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : The atomic mass of C = 12 u, H = 1 u and O = 16 u. So, molecular mass of CH3OH = 12 + 3 × 1 + 16 + 1 = 32 u. The molecular mass of C2H5OH = 12× 2 + 5 × 1 + 16 + 1 = 46 u. The molecular mass of C3H7OH = 12 × 3 + 7 × 1 + 16 + 1 = 60 u. And molecular mass of C4H9OH = 12 × 4 + 9 × 1 + 16 + 1 = 74 u. (a) The difference in the molecular formulae of CH3OH and C2H5OH is CH2. The difference in the molecular masses of CH3OH and C2H5OH is 46 – 32 = 14 u. (b) The difference in the molecular formulae of C2H5OH and C3H7OH is CH2. And the difference in the molecular masses of C2H5OH and C3H7OH is 60 – 46 = 14 u. (c) The difference in the molecular formulae of C3H7OH and C4H9OH is CH2. And the difference in the molecular masses of C3H7OH and C4H9OH is 74 – 60 = 14 u. (i) Yes, there is a similarity in the difference between their molecular formulae and molecular masses. Their molecular formulae differ by CH2 (1 carbon atom and 2 hydrogen atoms), and their molecular masses differ by 14 u. (ii) These alcohols can be arranged in the order of the increasing carbon atoms as follows : CH3OH, C2H5OH, C3H7OH, C4H9OH Yes, we can call it a homologous series. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : NOTE: Saturated hydrocarbons will generally give a clean flame while unsaturated carbon compounds will give a yellow flame with lots of black smoke. Now, Camphor & Naphthalene are unsaturated hydrocarbons. So they burn with yellow flame and leave residues. Alcohol is saturated and burns with clean blue flame. This results in a sooty deposit on the metal plate " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Limiting the supply of air results in incomplete combustion of even saturated hydrocarbons giving a sooty flame When do you get a flame? - In presence of a sufficient supply of air with oxygen, it gives a blue flame. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : i. When KMnO4 is added, its purple colour disappears initially. ii. Why does the colour of potassium permanganate not disappear when excess is added? -- Because all the alcohol gets consumed and the reaction stops. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : i. We observed a product (Sodium ethoxide) with hydrogen gas. ii. How will you test the gas evolved? -- When a burning spitter is brought near to the gas, the gas burns with pop sound. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This is esterification reaction, Product obtained is ester, having sweet smell. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Foam is formed with difficulty and an insoluble substance (scum) remains after washing with water. This is caused by the reaction of soap with the calcium and magnesium salts, which cause the hardness of water. Hence you need to use a larger amount of soap. This problem is overcome by using another class of compounds called detergents as cleansing agents. In which test tube do you get more foam?- Distilled water test tube. In which test tube do you observe a white curdy precipitate?- Hard water test tube. Do both test tubes have the same amount of foam?- No. The test tube containing detergent has more foam. In which test tube is a curdy solid formed? -- In the test tube containing soap. " 10th मतलब ?? - Shobhit Nirwan "  Ch-5: Life Processes Activity to demonstrate that Chlorophyll is necessary for Photosynthesis Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take a potted plant with variegated leaves – for example, money plant or crotons. Keep the plant in a dark room for three days so that all the starch gets used up. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Now keep the plant Take in sunlight about 2 cm forlong about six hours. magnesium ribbon. Pluck a leaf from the plant. Clean it with sand paper. and trace them on a Mark the green areas in it sheet of paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Dip the leaf in boiling water for a few minutes. other end. After this, immerse it in a beaker containing alcohol. Carefully place ThetheMagnesium above beaker Ribbon startsand in a water-bath burning. heat till the alcohol begins to boil. BUT IT'S NOT BURNING ALONE. Now dipIt the starts leaf burning in a dilute with a WHITE solution of iodineDAZZLING FLAME. for a few minutes. And Takenow out theto leaf collect the off and rinse Magnesium Oxide Powder hold it over a the iodine solution. Observe the colour of the leafWatchand compare Glassthis with the tracing of the leaf done in the beginning. Question 1. What happens to the colour of the leaf? What is the colour of the solution? Answer. The green leaf becomes colourless. On immersing green leaf in a alcohol, chlorophyll responsible for its green colour gets dissolves in alcohol. The colour of the alcohol solution turns green Question 2. What can you conclude about the presence of starch in various areas of the leaf? Answer. The green areas of leaf, which turns dark blue on dipping in iodine solution, indicate the presence of starch where as colorless part of leaf show no formation of starch. From this activity we can conclude that chlorophyll is essential for photosynthesis " 10th मतलब ?? - Shobhit Nirwan "  Activity to show that amount of Carbon Dioxide (CO2), essentially affects the process and outcome of Photosynthesis ChaloChalo Ab Ise AASAN Ab Ise AASANBHASHA BHASHA MEIMEI Samajhte Samajhte hai : hai : Take potted Take two healthy aboutplants 2 cmwhichlong are magnesium ribbon nearly the same size.. Keep them in a dark roomClean for it with three sand paper. days. Hold the magnesium ribbon with a pairplates. Now place each plant on separate glass Place,aand of tongs watch-glass start heating its containing potassium hydroxide by the side of one of the plants. The other end. potassium hydroxide is used to absorb carbon dioxide. The Magnesium Ribbon starts burning. Cover both plants with separate bell-jars as shown in Fig.. BUT IT'S NOT BURNING ALONE. Use Vaseline to seal the bottom of the jars to the glass plates so that the set- It starts burning with a WHITE DAZZLING FLAME. up is air-tight. And now Keep the to collect plants the Magnesium in sunlight Oxide Powder hold it over a for about two hours. Pluck a leaf from each plant and WatchcheckGlass for the presence of starch as in the above activity. Question 1. Do both the leaves show the presence of the same amount of starch? Answer. No, both the leaves do not show the presence of the same amount of starch, because in photosynthesis starch is produced using sun light, chlorophyll and CO2. In first set up availability of CO2 will be less for making starch by the plant leaves, as potassium hydroxide (KOH ) absorb the CO2. In second plant setup, the leaves will have more amount of starch. Question 2. What can you conclude from this activity? Answer. From this activity, we can conclude that amount of Carbon Dioxide (CO2) , essentially affects the process and outcome of photosynthesis. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN other end.MEI Samajhte hai : BHASHA Thesolution Take 1 mL starch Magnesium Ribbon (1%) in two starts test tubes burning. (A and B). Add 1 mL saliva toBUT IT'S ANOT test tube BURNING and leave ALONE. both test tubes undisturbed for 20-30 It starts burning with a WHITE DAZZLING FLAME. minutes. And Nownow add a tofew collect the drops of Magnesium dilute Oxide iodine solution Powder to the hold it over a test tubes. Question 1. In which test tube doWatchyou observe Glass a colour change? Answer. We will observe a colour change in test tube B, showing presence of starch. Where as test tube A will show no colour change as due to addition of saliva, starch is converted into sugar. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take some freshly prepared limeother waterend. in a test tube. The this Blow air through Magnesium lime water. Ribbon starts burning. BUT IT'S NOT BURNING ALONE. QuestionIt1.starts burning Note how long it with takesafor WHITE the limeDAZZLING water to turnFLAME milky?. Answer. And now Whentowe blow air collect through the mouth, theOxide Magnesium lime water in testhold Powder tube it turns milky over a within no time. Use a syringe or pichkari to Watch Glasspass air through some fresh lime water taken in another test tube. Question 2. Note how long it takes for this lime water to turn milky? Answer. When we use syringe or pichkari, to pass air through the lime solution, it takes much time and effort to turn the lime water milky. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Chalo AbClean it with Ise AASAN sand MEI BHASHA paper. Samajhte hai : Hold the Takemagnesium ribbon some fruit juice with or sugar a pair solution andof tongs add some ,yeast and tostart this. heating Take this its other mixture in a test tube fitted with end. cork. a one-holed Fit the cork The with aMagnesium bent glass tube. Dip thestarts Ribbon free end of the glass tube into a burning. test tube containing BUTfreshly prepared IT'S NOT lime water. BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. Question 1. What change is observed in the lime water and how long does it And now to collect the Magnesium Oxide Powder hold it over a take for this change to occur? Answer. The lime water becomesWatch milky asGlass carbon dioxide is produced by mixing yeast in sugar along with alcohol. Time taken for this change to occur, should be observed by students themselves. Question 2. What does this tell us about the products of fermentation? Answer.The products of fermentation are alcohol and carbon dioxide. " 10th मतलब ?? - Shobhit Nirwan "  Ch-6: Control & Coordination Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. Have the old parts of BUT the IT'S shootNOT and BURNING root changedALONE. direction? Answer: TheIt starts old partsburning with of the shoot a WHITE and root haveDAZZLING FLAME no noticeable change. in And now to collect the Magnesium Oxide Powder hold it over a direction. Watch Glass Are there differences in the direction of the new growth? Answer: New growth parts show change in direction. i.e., shoot bends towards light and roots bend away from it. What can we conclude from this activity? Answer: Shoots show phototropism and the roots show geotropism. " 10th मतलब ?? - Shobhit Nirwan "  Ch-7: Reproduction Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean Activity Observation: Under the it with sandwepaper. microscope, see yeast reproducing by Hold thebuds. forming magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning Activity Observation: A whitewith a WHITE cottony DAZZLING mass appears FLAMEof. moist on the surface Andwhich bread now turns to collect the Magnesium black within Oxide few days. The white Powder cottony masshold is dueittoover a growth Watch of bread mould (Rhizopus). The spores Glassare present in the air. They settle of fungus on the moist bread and germinate to form white cottony mass of vegetative mycelium. The vegetative mycelium develops asexual sporangia which are black in colour. Each sporangium contains hundreds of minute black- coloured spores. These spores are dispersed in air to germinate on suitable substratum Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Activity Observation: Spirogyra, simply breaks up into smaller pieces upon Clean it with sand paper. maturation. These pieces or fragments grow into new individuals Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass " 10th मतलब ?? - Shobhit Nirwan " Activity Observation: The potato pieces having buds gradually grows and develops. But there is no growth and development in potato pieces without buds. Which are the potato pieces that give rise to fresh green shoots and roots? The pieces with buds give rise to fresh green shoots and roots. Activity Observation: Portion of Money plant with at least one leaf grows and gives rise to fresh leaves. But money plant without leaf dies. What can you conclude from your observations? Money plant with green leaves can synthesize food through photosynthesis and able to grow into a plant, through vegetative propagation. Activity Observation: Two seed cotyledons are separated by radicle and plumule formation. " 10th मतलब ?? - Shobhit Nirwan "  Ch-9- Light: Reflection & Refraction Chalo AbAb Chalo Ise IseAASAN BHASHA AASAN BHASHA MEIMEI Samajhte Samajhte hai : hai : Take of The curved surface about 2 cm a shining longcould spoon magnesium ribbon be considered. as a curved mirror. One Convex surface and Clean other it with sand concave paper. surface. Sp for answering the Holdquestions keep in mindribbon the magnesium the properties with aofpair bothof thetongs spherical mirrors. , and start heating its Question 1: Do you get the image?other Is it smaller end. or larger? Yes. The image on the outer curved surface is smaller. The Magnesium Ribbon starts burning. Question 2: Move the spoon slowly away from your face. Observe the image. How does it change? BUT IT'S NOT BURNING ALONE. It starts The size of the burningdecreases. image gradually with a WHITE DAZZLING FLAME. And now Question to collect 3: n Reverse the Magnesium the spoon and repeat the Oxide Powder Activity. How hold it over a does the image look like now? Watch Glass The image at its concave side is real, inverted and diminished. Question 4: Compare the characteristics of the image on the two surfaces. The image at its concave side is real, inverted and diminished. If the spoon is moved away, the image becomes smaller. Image at the convex side is virtual, erect & diminished. If the spoon is moved away, the image becomes smaller. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN other end.MEI Samajhte hai : BHASHA The paper atThe first begins to burn producing Magnesium smoke. burning. Ribbon starts Eventually it may even catch fire. BUT IT'S NOT BURNING ALONE. Why does it burn? The light from the Sun is converged at a point, as a sharp, It starts burning with a WHITE DAZZLING FLAME. bright spot by the mirror. In fact, this spot of light is the image of the Sun on And the now sheetto of collect the paper. This Magnesium point is the focus Oxide Powder of the concave hold it over a mirror. The heat produced due to theWatch Glass of sunlight ignites the paper. The concentration distance of this image from the position of the mirror gives the approximate value of focal length of the mirror " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN other end.MEI Samajhte hai : BHASHA This activity isThe Magnesium basically to find outRibbon starts the positions burning. of the image formed by the concave mirrors, their BUTnature, size etc. IT'S NOT BURNING ALONE. You will see in the above Activity It starts burning with a WHITE that the nature, position FLAME DAZZLING and size of. the image formed by a concave mirror depends on the position of the object in And now to collect the Magnesium Oxide Powder hold it over a relation to points P, F and C. Watch Glass The image formed is real for some positions, nd virtual for other. The image is either magnified, reduced or has the same size, depending on the position of the object. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This activity is basically to find out the positions of the image formed by the Take about 2 cm long magnesium ribbon. convex mirrors, their nature, size etc. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. Question 1: Observe the image of the pencil in the mirror. Is the image erect And now to collect the Magnesium Oxide Powder hold it over a or inverted? Is it diminished or enlarged? Watch Glass Its image in the mirror is erect and diminished. Question 2: Move the pencil away from the mirror slowly. Does the image become smaller or larger? The image becomes smaller. Question 3: Repeat this Activity carefully. State whether the image will move closer to or farther away from the focus as the object is moved away from the mirror? The image moves closer to the focus. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASAN other end.MEI Samajhte hai : BHASHA This activity isThe Magnesium basically to find outRibbon which of starts burning. these mirrors will give the full image of a large BUTobject?IT'S NOT BURNING ALONE. Observation: You can see a full-length image of a tall building/tree in a It starts burning with a WHITE DAZZLING FLAME. small convex mirror. One such mirror is fitted in a wall of Agra Fort facing Taj And now to collect the Magnesium Oxide Powder hold it over a Mahal. Watch Glass " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Chalo Take Ab Ise 2AASAN about cm longBHASHA MEI Samajhte magnesium hai :. ribbon These activities are toClean understand the sand it with phenomenon paper.of refraction of light. Light does not travel in the same direction in all media. It appears that when Hold the magnesium ribbon with a pair of tongs , and start heating its travelling obliquely from one medium to another, the direction of propagation other end. of light in the second medium changes. The Magnesium Ribbon starts burning. Question 1: With your BUT eye IT'S NOTabove to a side BURNING water,ALONE. try to pick up the coin in one go. Did youIt succeed starts burning in picking with a WHITE up the coin? DAZZLING FLAME. NoAnd now to collect the Magnesium Oxide Powder hold it over a Question 2: Repeat the Activity.Watch Why didGlass you not succeed in doing it in one go? Reflected light coming from the submerged coin in water (denser medium), on entering air (rarer medium), bend away from the normal due to refraction of light and image size becomes larger than its actual size. Thus, coin appears to be closer than its actual distance. Question 3: Keep looking for the coin from your position. Does the coin becomes visible again from your position? How could this happen? Yes. The coin becomes visible again. This is because the coin appears slightly raised above its actual point due to refraction of light. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Draw a thick straight line in ink, over a sheet of white paper on a table. Place a glass slab over the line in such a way that one of its edges makes an angle with the line. Question: Look at the portion of the line under the slab from the sides. What do Chalo Ab Ise AASAN you observe? Does theBHASHA line underMEI Samajhte the glass hai : to be slab appear bent at theTake edges?about 2 cm -- Yes, long the line magnesium under ribbon the slab appears. bent and it to be is due to refraction. Clean it with sand paper. Next, place the glass slab such that it is normal to the line. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Question: What do you observe Glass now? Does the part of the line under the glass slab appear bent? -- No, the part of the line under the glass slab does not appear bent because the ray of light is perpendicular to the slab and does not make any angle, so it appears straight. OBSERVATION: This activity demonstrates the phenomenon of refraction and for normal incidence, there no refraction occurs. Question: Look at the line from the top of the glass slab. Does the part of the line beneath the slab, appear to be raised? why does this happen? -- Yes, the part of the line beneath the slab appears to be raised because of refraction. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium Oxide Powder hold it over a Watch Glass " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. These activities TheareMagnesium to understandRibbon the phenomenon of refraction of light starts burning. through glass slab. BUT IT'S NOT BURNING ALONE. Here, the light ray has changed its direction at points O and O'. Both the It starts burning with a WHITE DAZZLING FLAME. points O and O' lie on And The now to at light ray collect point Othe Magnesium enters from a rarerOxide mediumPowder (air) to ahold denseritmedium over a (glass). The light ray Watch Glass Compare the angle of incidence with angle of refraction at both refracting surfaces AB & CD. A ray EO is obliquely incident on surface AB, called incident ray. OO′ is the refracted ray and O′ H is the emergent ray. You may observe that the emergent ray is parallel to the direction of the incident ray. Why does it happen so? The However, the light ray is shifted sideward slightly. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its Chalo Ab Ise AASANother end.MEI Samajhte hai : BHASHA The to The paper begins Magnesium burn producingRibbon smoke.starts burning. It may even catch fire after a while. BUT IT'S NOT BURNING ALONE. It starts Why does burning this happen? The with a WHITE light from the SunDAZZLING FLAMErays constitutes parallel. of light. These And nowraysto were converged collect by the lens at the the Magnesium Oxidesharp bright spot Powder formed hold on the it over a paper. In fact, the bright spot you got on the paper is a real image of the Sun. Watch Glass The concentration of the sunlight at a point generated heat. This caused the paper to burn. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This activity is basically to find out the positions of the image formed by the convex lens, their nature, size etc. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This activity is basically to find out the positions of the image formed by the concave lens, their nature, size etc. " 10th मतलब ?? - Shobhit Nirwan "  Ch-12- Electricity Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Chalo AbClean Ise AASAN BHASHA it with sandMEI Samajhte hai : paper. This activity is basically for obtaining V-I graph (Ohm's Law). Hold the magnesium ribbon with a pair of tongs , and start heating its First, only one cell is the voltage source, note down the ammeter and other end. voltmeter readings and fill in the table provided. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. It starts burning with a WHITE DAZZLING FLAME. And now to collect the Magnesium i1 v1 Oxide Powder v1/i1 hold it over a i2 v2 v2/i2 i3Watch Glassv3 v3/i3 i4 v4 v4/i4 We observed that approximately the same value for V/I is obtained in each case. Thus the V–I graph is a straight line that passes through the origin of the graph, as shown in Fig. 12.3. Thus, V/I is a constant ratio. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : BUT IT'S This activity is basically NOT to study BURNING about electricalALONE. resistance of a conductor. It starts burning with a WHITE DAZZLING FLAME. In this Activity we observe that the current is different for different And Whynow to differ? do they collect the Magnesium Certain Oxide components offer Powder an easy hold path for theitflow over of a Watch electrical current while the others resistGlass the flow. We know that the motion of electrons in an electric circuit constitutes an electric current. The electrons, however are not completely free to move within a conductor. They are restrained by the attraction of the atoms among which they move. Thus, motion of electrons through a conductor is retarded by its resistance. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This activity is basically to find out factors on which resistance of a conductor depends. We know, Answering the questions keeping in mind this only. Question: Does the current depend on the length of the conductor? - Yes Question: Does the current depend on the area of cross-section of the wire used? - Yes " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This activity is basically to understand that the current in the ammeter is the same, independent of its position in the electric circuit. It means that in a series combination of resistors the current is the same in every part of the circuit or the same current through each resistor. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : This activity is basically to understand that the potential difference V is equal to the sum of potential differences V1 , V2 , and V3. That is the total potential difference across a combination of resistors in series is equal to the sum of potential difference across the individual resistors. V = V1 + V2 + V3 *Activity 12.6 is derivation of equivalent resistance formula for parallel. " 10th मतलब ?? - Shobhit Nirwan "  Ch-13- Magnetic Effects Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. BUT IT'S NOT BURNING ALONE. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : It starts burning with a WHITE DAZZLING FLAME. We see that the needle is deflected which means that the electric current through And the nowwire copper to has collect the Magnesium produced Oxide a magnetic effect. ThusPowder hold we can say thatitelectricity over a and magnetism are linked to eachWatch other Glass Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : Take about 2 cm long magnesium ribbon. Clean it with sand paper. Hold the magnesium ribbon with a pair of tongs , and start heating its other end. The Magnesium Ribbon starts burning. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : BUT IT'S NOT BURNING ALONE. The magnet exerts its influence in the region surrounding it. Therefore the iron It starts filings experience burning a force. with thus The force a WHITE exertedDAZZLING FLAME makes iron filings. to arrange in a And now to collect pattern(Fig-13.2). the The region Magnesium surrounding OxideinPowder a magnet, which thehold force it of over the a magnet can be detected, is said to Watch have aGlass magnetic field. The lines along which the iron filings align themselves represent magnetic field lines. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : We shall first consider the pattern of the magnetic field around a straight conductor carrying current. What happens to the deflection of the compass needle placed at a given point if the current in the copper wire is changed? To see this, vary the current in the wire. We find that the deflection in the needle also changes. In fact, if the current is increased, the deflection also increases. It indicates that the magnitude of the magnetic field produced at a given point increases as the current through the wire increases. What happens to the deflection of the needle if the compass is moved away from the copper wire but the current through the wire remains the same? To see this, now place the compass at a farther point from the conducting wire (say at point Q). What change do you observe? We see that the deflection in the needle decreases. Thus the magnetic field produced by a given current in the conductor decreases as the distance from it increases. From Fig. 13.6, it can be noticed that the concentric circles representing the magnetic field around a current-carrying straight wire become larger and larger as we move away from it. Does the direction of magnetic field lines get reversed if the direction of current through the straight copper wire is reversed? -- The direction of magnetic field lines is reversed if the direction of current through the copper wire is reversed. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : The displacement of the rod (AB) suggests that: A force is exerted on the current-carrying aluminium rod when it is placed in a magnetic field. The direction of force is also reversed when the direction of current through the conductor is reversed. Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : If the south pole of the magnet is moved towards the end B, the deflections in the galvanometer would just be opposite to the previous case. When the coil & magnet are stationary, there is no deflection in the galvanometer. This activity shows that the motion of a magnet with respect to the coil produces an induced potential difference, which sets up an induced electric current in the circuit. " 10th मतलब ?? - Shobhit Nirwan "  Chalo Ab Ise AASAN BHASHA MEI Samajhte hai : As soon as the current in coil-1 reaches either a steady value or zero, the galvanometer in coil-2 shows no deflection. We conclude that a potential difference is induced in coil-2 whenever the electric current through the coil-1 is changing (starting or stopping). Coil-1 is called the primary coil and coil-2 is called the secondary coil. As the current in the first coil changes, the magnetic field associated with it also changes. Thus the magnetic field lines around the secondary coil also change. Hence the change in magnetic field lines associated with the secondary coil is the cause of induced electric current in it. This process, by which a changing magnetic field in a conductor induces a current in another conductor, is called electromagnetic induction " 10th मतलब ?? - Shobhit Nirwan "