Class 10 CBSE SCIENCE PT-1 Complete Revision | Most Important Concepts & Questions

[00:00:04]Come on. Come on. Complete.

[00:00:12]Yes.

[00:00:14]Session start.

[00:00:28]Yes. Hello Ki. Hello. Hello everyone.

[00:00:32]Okay. So 10 standard CBSC students. So in the session. Yes. Hello stand.

[00:00:54]Hello. Hello. Hello. Hello.

[00:01:02]standard students.

[00:01:10]Important questions.

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[00:01:58]CBS Max CBSC students chemistry physics and biology.

[00:02:14]Okay.

[00:02:20]Three lessons. Okay. Physics, light chapter, chemistry, chemical reactions and equations and biology life process chapter. Okay. In the mood chapters important questions, different types of questions.

[00:02:38]So yes, you guys ready for the session?

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[00:02:46]CBS CBC students. Yes.

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[00:03:29]Okay. Okay. Byebye.

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[00:03:44]Very good. Okay.

[00:03:48]Period.

[00:04:03]Okay.

[00:04:08]Okay. So maximum yes CBSC state marathon Okay.

[00:04:34]Okay.

[00:04:39]Yes.

[00:04:46]Important questions.

[00:04:49]Okay. So, chemical reactions and equations. uh life process light reflection and refraction questions.

[00:04:59]So first chemical reactions and equations. Okay. So questions. Okay. So we go for the questions. Berium chloride on reacting with ammonium sulfate forms berium sulfate and ammonium chloride.

[00:05:15]CBC.

[00:05:18]Okay.

[00:05:21]CBC students.

[00:05:35]Okay.

[00:05:37]25 exam four chapter light process chemical equations reactions and equations and human high. Okay.

[00:05:49]Okay.

[00:05:58]Okay. Thank you so much. Okay.

[00:06:05]I'm taking three chapters. Okay. So, thank you so much. Okay.

[00:06:12]Okay. The first question. Berium chloride on reacting with ammonium sulfate forms berium sulfate and ammonium chloride. Berium chloride.

[00:06:22]Ammonium sulfate. It forms berium sulfate and ammonium chloride. Which of the following correctly represents the type of reaction?

[00:06:32]reaction berium chloride on reacting with ammonium sulfate. Okay. Berium sulfate and ammonium chloride form. So type of reaction type of reaction.

[00:06:48]Yes.

[00:06:51]Yes.

[00:06:55]Okay.

[00:06:59]Berium chloride in a ammonium sulfate NH4 twice SO4 okay gives Ba2 SO4 BO4 plus ammonium chloride okay so what is this type of reaction displacement of displacement reaction double displacement reaction Okay.

[00:07:41]Okay. So there is mutual exchange of ions there is mutual exchange of ions.

[00:07:50]Double displacement precipitate insoluble.

[00:08:04]Okay.

[00:08:06]Precipitation reaction.

[00:08:09]So option two and option four. Option two and option four. So option D is the right answer. Option D the correct answer.

[00:08:20]question.

[00:08:22]Okay.

[00:08:26]Please look into it very very carefully.

[00:08:29]Okay.

[00:08:40]Okay. Throw match. Okay.

[00:08:46]Okay.

[00:08:47]Next question. A brown and bright element X. A brown and bright element X when heated in the presence of air turns into a black substance Y. Okay. If hydrogen gas is passed over this heating material again X is obtained. Identify X and Y.

[00:09:20]Okay. A brown and bright element X when eaten in the presence of air turns into black substance Y. If hydrogen gas is passed over this eating material again X is obtained. Identify X and Y. Identify X and Y.

[00:09:34]brown and bright element in the presence of so nothing but copper.

[00:09:50]Okay. So A is nothing but copper. A is nothing but copper.

[00:10:06]Okay. So, A is nothing but copper. Okay.

[00:10:09]If the prespper hydrogen gas is passed over this material again.

[00:10:21]Okay. So, Cydroen gas. Very good. Very good. So Cy okay again you are getting back the Cu plus H2O.

[00:10:41]Okay. So this is A. This is A and this is sorry A this is X and this is Y. This is Y. Okay. Very good. Very good. So X so this is nothing but an oxidation reaction. Okay. And addition of oxygen this is oxidation.

[00:11:04]Removal of oxygen removal of oxygen. So this is reduction.

[00:11:10]Okay. So option A is the right answer. X copper and Y copper oxide.

[00:11:17]Very good. Question.

[00:11:20]Identify the correct oxidant and reductant in the following reaction oxidant and what is correct reductant.

[00:11:29]Okay. So which is the correct oxidant and correct reductant in the following uh reaction? Pbs plus 4 H2O2 gives Pb4 plus 4 H2O.

[00:11:40]This is lead sulfide and this is hydrogen peroxide. This is lead sulfate plus H2O. Okay. oxid.

[00:11:51]I have doubt how copper oxidation remove. How copper.

[00:12:03]Option C. Money. I have copper oxidation removed.

[00:12:15]reducing agent. So copper oxide gets reduced to copper. Okay. So this is removal of in so it forms H2O. So copper oxide is converted into copper. So removal of oxygen. So reduction.

[00:12:36]Thank you so much. Thank you so much. So what is the answer for this? What is the answer for this? So first what do you mean by oxidant and what do you mean by reductant oxidant and reductant?

[00:13:01]Yes.

[00:13:03]Yes. Very good money.

[00:13:08]oxygen has become PBS4 oxidiz got reduced. This is reduced oxidized.

[00:13:33]So oxygen.

[00:13:38]Okay.

[00:13:50]reduction. Okay. Oxidentum oxidizing agent.

[00:13:55]Oxidentum oxidizing agent.

[00:14:01]Yes.

[00:14:10]Yes.

[00:14:15]So oxid 12th portion start already. So oxidant nothing but oxidizing agent.

[00:14:22]Oxidizing agent oxidant and reductant reductant reducing agent.

[00:14:37]Okay.

[00:14:46]The substance that reduced substance reduced oxidizing agent. Okay.

[00:14:55]Substance oxidized reducing agent.

[00:15:06]Okay. Okay. So PBS oxidize reductant. Okay. So PBS is a reductant and H2 oxidant. Okay. So option C is the right answer. Very good. Very good. Correct.

[00:15:26]Question.

[00:15:28]Which of the following reactions is not balanced? Which of the following reactions is not balanced?

[00:15:49]Yes.

[00:15:56]Okay. 12th portion.

[00:16:01]Sorry. Sorry. Sorry.

[00:16:05]balanced reaction. So this is reactant.

[00:16:08]These are products. Okay.

[00:16:15]Oxygen 3 4 5 6. So this is balanced.

[00:16:19]Okay. So this is balanced.

[00:16:25]Okay. 20 Hydrogen 20 oxygen 24 oxygen 16 + oxygen 8 are 16 16 + 10 26 okay so 12 are 24 oxygen and 10 + 16 26 oxygen so which is the right answer which of the four reaction is not balanced so this is not balanced This is not balanced.

[00:17:02]6 hydrogen 3 2 are 6 6 + 3 2's are 6 6 + 6 12 hydrogen 6 oxygen and 3 2 are 6 oxygen. So this is balanced.

[00:17:16]Okay. Next four nitrogen in four nitrogen 4 3's are 12 hydrogen and 6 2 are 12 hydrogen 5 are 10 oxygen 4 + 6 10 oxygen so this is also balanced so in the equation balance option B is the right answer very good very good answer okay sodium reacts with water to form Sodium hydroxide and hydrogen gas. Sodium water react sodium hydroxide and hydrogen gas form.

[00:17:56]The balance the equation which represents the above reaction. Okay. In the reaction equation, sodium reacts with water to form sodium hydroxide. Sodium reacts with water to form sodium hydroxide and hydrogen gas. products and reactants 2.

[00:18:21]So 2 Na 2 Na. Okay. 2 Four hydrogen 2 are four hydrogen. Two oxygen two oxygen. So this is balanced. Okay. Next number.

[00:18:37]Okay. Huh? 2 Na 2 Na two hydrogen in four hydrogen. So this is not balanced.

[00:18:45]Okay. 2 N.

[00:18:47]So this is also not balanced. Okay. So equation. So very good. Very good.

[00:18:54]Very good. So option B is the right answer in the equation.

[00:18:59]Okay.

[00:19:02]Balancing the chemical reaction.

[00:19:06]It is important to balance a chemical equations to satisfy the law of conservation of mass. Okay. Which of the following statements of the law is correct? Law of conservation of mass.

[00:19:21]Come on.

[00:19:27]Law of conservation of mass.

[00:19:30]Come on. Which of the following statements of the law is correct?

[00:19:39]Come on. So the total mass of the elements present in the reactants is equal to the total mass of the elements present in the products. Now first the number of atoms of each element remains the same before and after a chemical reaction. The chemical composition of the reactants is the same before and after the reaction. Okay. mass can neither be created or nor can it be destroyed in a chemical reaction.

[00:20:05]Okay. So incorrect statement. Okay.

[00:20:13]Incorrect statement. Okay.

[00:20:20]Okay. So a mask can neither be created.

[00:20:26]Mass can neither be created.

[00:20:33]So which is the right answer?

[00:20:36]Bing. The number of atoms of each element remains the same before and after a chemical reaction. Yes.

[00:20:48]The total mass of the elements before present in the reactants is equal to the total mass of the elements present in the products. Okay.

[00:20:59]But which is the right answer?

[00:21:02]Okay. So, so you have to say the right answer.

[00:21:09]Okay. So, which is the right answer?

[00:21:11]Come on. Come on. Which is the right answer?

[00:21:15]So law of conservation of law of conservation of mass.

[00:21:29]Yes.

[00:21:33]So the law of conservation of mass. Very good. Very good.

[00:21:43]But chemical composition of the reactants is the same before and after the reaction.

[00:21:50]Incorrect statement. Okay. So option C correct answer. Okay. Incorrect statement question.

[00:21:58]Okay. Which of the following is not correct? Which of the following is incorrect?

[00:22:08]Which of the following is incorrect?

[00:22:10]Come on. Answer.

[00:22:12]Hello. Hello. Which of the following is incorrect? Z4 gives reactivity.

[00:22:29]Please stop calling me.

[00:22:33]Please stop calling me.

[00:22:42]careless zebra instead.

[00:22:52]Try learning how copper saves gold.

[00:23:07]So potassium, sodium, calcium, magnesium. him.

[00:23:41]Hydrogen, copper, silver, gold.

[00:23:57]color zebra.

[00:24:01]Okay. So, this is copper. This is copper.

[00:24:16]So, copper.

[00:24:18]Zinc is less reactive than copper.

[00:24:22]Zinc is elements more reactive. So more reactive less reactive.

[00:24:32]So copper can displace zinc. Zinc cannot displace copper. Zinc it cannot displace copper. Okay. So zinc copper zinc but copper can displace zinc. Okay. So which is the right answer? First one see Fe plus CO4 gives FO4 solution will displace copper from copperf which of the following reaction is incorrect.

[00:25:23]Which of the following reaction is incorrect and correct reaction? This is correct reaction. This is a correct reaction.

[00:25:32]And the correct reaction magnesium can displace hydrogen. Magnesium. Magnesium.

[00:25:38]Magnesium can displace hydrogen.

[00:25:43]Correct. And Agnu, silver and copper.

[00:25:47][snorts] Silver and copper. Silver.

[00:25:49]Silver. Silver and copper.

[00:25:53]Okay.

[00:25:55]Copper saves gold. Okay. So, copper silver question. So, B is the right answer. So first one first one.

[00:26:22]Yes.

[00:26:26]Yes.

[00:26:29]Come on. Come on. Come on. Second one.

[00:26:31]First one. Tapa.

[00:26:44]Okay.

[00:26:49]So this is calcium.

[00:26:52]Copper.

[00:26:55]So zinc is more reactive than copper. So zinc can displace copper. Okay. So option A is right.

[00:27:04]So option B is the incorrect one.

[00:27:09]Okay. So in the reactivity series Okay. So in the reactivity series potassium, sodium, calcium, magnesium, carbon, zinc, iron, tin, lead, hydrogen, copper, silver, gold. Okay. reactivity.

[00:27:39]Okay.

[00:27:43]Calcium calcium.

[00:27:46]Okay. This is calcium. Okay. So, zinc zinc.

[00:27:54]So, option A is correct. Option A.

[00:27:57]Option B. Silver and copper. Okay.

[00:28:00]Silver and copper. Copper. Silver.

[00:28:03]silver.

[00:28:06]So, option B is the incorrect one. Okay.

[00:28:10]Identify the correct statements.

[00:28:13]Identify the correct statement. This is B. Okay. PBO plus C gives PB plus CO.

[00:28:21]Okay. So, which is the correct statement? Which is the correct statement?

[00:28:26]Come on. Which is the correct statement?

[00:28:28]Come on.

[00:28:32]Yes.

[00:28:35]Which is the correct statement?

[00:28:39]So lead.

[00:28:46]So this is reduction reaction. This is reduction and carbon.

[00:28:51]So this is oxidation. This is oxidation.

[00:28:54]So let Okay. Okay. So this is oxidizing agent and so this is reducing agent. Okay. So this is reducing agent.

[00:29:18]P is oxidized.

[00:29:20]This is wrong. This is wrong. P act as an oxidizing agent. Tap the reducing agent. C act as a reducing agent.

[00:29:29]Correct. Okay. Reaction does not represent a redux reaction. Redux reaction. So option C is the right answer. Very good. Very good. Very good.

[00:29:40]Very good. Okay. Question. A substance which oxidizes itself and reduces others is known as dash.

[00:29:52]But it will reduce others.

[00:29:56]A substance which oxidizes itself and reduces others. And the substances what do we call what do we call that substances? A substance which oxidizes itself and reduces others. And the substance come on. Come on.

[00:30:19]Yes. Yes. Yes. Yes.

[00:30:35]Come on.

[00:30:40]Very good. Your substance oxidize and reduces others. Okay. We call it as reducing agent. Okay. Reducing agent.

[00:30:52]Okay. So option B correct answer option B is the right answer the question take about 5 ml of dilute HCL take about 5 ml of dilute HCL in a test tube and add a few pieces of fine zinc granules to it which gases evolve take about 5 ml of social marath 10 state already marathon.

[00:31:25]Okay. Take about 5 ml of dilute HCL test 5.

[00:31:30]Add a few pieces of zinc in it. Okay.

[00:31:33]Which gases involved? Zinc plus hydrochloric acid.

[00:31:38]Zinc chloride plus gas for gas form. Okay. So which is the right answer? Option B correct answer question. When aquous solution of potassium iodide and lead nitrate are mixed. Potassium iodide and lead nitrate.

[00:32:01]Okay. B aqua solution of potassium iodide and lead nitrate an insoluble substance separate potassium iodide and lead nitrate. Potassium iodide and lead nitrate PBN3 twice.

[00:32:21]Okay. Potassium iodide and lead nitrate are mixed. an insoluble substance insoluble substance the balanced chemical equation for the reaction involved. Okay. So the balanced chemical equation for the reaction in Okay. So KI plus PBN3 gives KNO3 KO3 plus Pbi2.

[00:32:47]So which is the right answer? Which is the right answer? Come on.

[00:32:52]Which is the right answer?

[00:32:56]Which is the right answer?

[00:33:04]Okay. So balance 23.

[00:33:07]Okay. So yes. So this is balance.

[00:33:16]Yes. So option B.

[00:33:19]Option B is the right answer.

[00:33:25]A metal ribbon X burns in oxygen.

[00:33:33]It forms a white ash Y. Okay. The correct description of X Y.

[00:33:45]So X Y X Y the correct description of X Y and the type of reaction the correct description of X Y and the type of reaction. Come on X and magnesium Y and magnesium oxide. Okay. Type of reaction in a combination reaction. Exactly. So option B correct answer the question.

[00:34:10]Name the type of chemical reaction which takes place when climb is added to water.

[00:34:18]Type of reaction water.

[00:34:35]Calcium hydroxide form.

[00:34:38]calcium hydroxide form. Okay. So, heat energy. So, it is a combination reaction as well as this is an exothermic reaction.

[00:34:51]Exothermic reaction. So, combination reactions exothermic reaction.

[00:35:03]What is a balanced chemical equation?

[00:35:06]Balanced chemical equation.

[00:35:09]What do you mean by balanced chemical equation? Come on. Balanced chemical equation and an equation with an equal number of atoms of each element on both sides of the equation side of the equation. Equal number of atoms of each element.

[00:35:26]Okay. Okay.

[00:35:34]chemical equation.

[00:35:37]Okay. So, balancing of chemical equation is very important.

[00:35:42]So, berium chloride reacts with aluminium sulfate to give aluminium chloride and berium sulfate.

[00:36:00]equation.

[00:36:04]Okay. So, two3 is then five here.

[00:36:25]Okay. So, what can I do? Try try try 3.

[00:36:46]So 3A 2 3 BA 3 BA. Okay. 3 2 are six chlorine. 3 2 6 chlorine aluminium two aluminium. Okay. Sulfur 3. Sulfur 3.

[00:37:04]Oxygen 43 are 12. Oxygen 4 3 12. Okay.

[00:37:10]So this reaction is the balanced chemical equation.

[00:37:16]Balanced chemical equation.

[00:37:19]Okay.

[00:37:22]Okay. So, balancing of chemical equation important.

[00:37:34]Yes.

[00:37:36]Okay.

[00:37:39]Question. Give the chemical name of the reactants as well as the products of the following chem.

[00:37:45]Okay.

[00:37:47]Write the balanc chemical equations for the following chemical reactions. Very good.

[00:37:54]Okay. So equation equation hydrogen plus chlorine gives hydrogen chloride.

[00:38:03]Hydrogen plus chlorine gives hydrogen chloride to balance. So balance I'll put two. So this is a balanced equation plus copper chloride gives lead chloride. Sorry lead chloride plus copper. Okay. So lead plus copper chloride gives lead chloride plus copper plus copper. Okay. So proper so everything is proper. So this is actually balanced. So this is actually balanced.

[00:38:47]Zinc oxide plus carbon gives zinc plus carbon monoxide.

[00:38:52]Zinc oxide plus carbon gives zinc plus carbon monoxide.

[00:39:00]This is also balanced. This is also balanced. Okay. So balance the chemical equations proper.

[00:39:08]Okay. Proper balancing of equations.

[00:39:12]Okay.

[00:39:14]Classify the following reactions into different types.

[00:39:19]Different different types of reactions of reaction.

[00:39:24]Okay. So first one Ag3 plus NaCl is giving Ag plus Na3. Ag3 plus NL gives Ag plus Na3. Yeah. So this is anion.

[00:39:43]So there is mutual exchange of ions between the reactants. Okay. So this is nothing but a double displacement reaction reaction. This is nothing but a double displacement reaction.

[00:40:04]double displacement reaction. Okay.

[00:40:08]Calcium oxide plus H2O gives calcium hydroxide. So calcium oxide calcium hydroxide. So this is a combination reaction.

[00:40:22]Combination reaction.

[00:40:26]This is a combination reaction.

[00:40:31]Okay. Clear?

[00:40:33]Zinc plus copper sulfate give zinc sulfate plus copper sorry third one 2 K3 gives 2 KL + 3 O2 so this is nothing but a decomposition reaction this is nothing but The decomposition reaction zinc plus copper sulfate gives zincfate plus copper. So zinc copper.

[00:41:17]So zinc sulfate plus copper.

[00:41:20]So this is nothing but a displacement reaction. This is nothing but a displacement reaction.

[00:41:32]Okay.

[00:41:34]I think it is clear.

[00:41:38]Okay. Double displacement combination thermal decomposition. Decomposition heat energy react that is thermal decomposition reaction.

[00:41:55]Okay. I think study the following equation of a chemical reaction. Hydrogen and chlorine is combining to give two HCl. So type of reaction type of reaction write a balance chemical equation of another example of this type of reaction. So hydrogen and chlorine combine hydrogen chloride for hydrogen chloride for so this is nothing but a combination reaction any type of reaction this is nothing but a combination reaction reaction combination reaction okay write a balance the chemical equation for another example of this type of reaction type of reaction example Okay. So where calcium oxide plus water in water gives calcium hydroxide. So this is an example of this is an example of combination reaction.

[00:43:04]How do organisms reproduce in a one shot?

[00:43:08]Okay. Don't worry.

[00:43:10]Don't worry.

[00:43:20]Yes. Yes. Yes.

[00:43:36]Okay.

[00:43:42]State the type of chemical reaction represented by the following. Okay. Type of reactions. A plus BC gives AC plus a displace. Okay. And it is forming AC. So this is nothing but a displacement reaction.

[00:44:00]This is a displacement reaction. This is a displacement reaction. A plus B is combining to give P. A plus B is combining to give C. So this is the combination reaction combination reaction.

[00:44:18]PQ plus RS gives PS plus RQ to exchange of reactants. Exchange of ions between the reactants. So this is nothing but double displacement reaction.

[00:44:31]Double displacement reaction.

[00:44:36]Okay. Clear? Yes.

[00:44:40]What component is the universe made up of?

[00:44:53]Yes. Question.

[00:44:58]Okay. Definition type of questions.

[00:45:02]Okay. Next question. mentioned with reason. The color changes observed when silver chloride is exposed to sunlight.

[00:45:13]Universe is made up of galaxies and galaxy is made up of solar system.

[00:45:23]Solar system is made up of planets.

[00:45:26]Planets are made up of matter. Matter is made up of elements. Element is made up of atoms.

[00:45:36]So mention the with reason the color change is observed when silver chloride is exposed to sunlight silver chloride and sunlight exposed AgClite exposed photo decomposition of silver chloride takes place which results in the formation of silver Silver.

[00:46:06]Okay. And color changes to gray. So silver is nothing but it will be in gray color and silver chloride color. So white color changes to gray color. White color changes to gray color. Okay. So color changes.

[00:46:32]What do you observe?

[00:46:45]Okay.

[00:46:55]Okay.

[00:47:03]absorb. Okay.

[00:47:16]Okay. Question. Copper powder is strongly heated in the presence of oxygen.

[00:47:23]Copper powder. Copper powder is strongly heated in the presence of oxygen.

[00:47:34]Copper is strongly heated in the presence of oxygen.

[00:47:38]CO form. Okay. I get two CO. So copper red in color reddish brown which is black color powder which is black powder.

[00:48:09]answer. A piece of zinc is dropped in a copper sulfate solution. Okay. Zinc.

[00:48:16]Okay. So, zinc is dropped in a copper sulfate solution. Zinc is dropped in a copper sulfate solution. Okay. So zinc is more reactive than copper.

[00:48:31]Important questions.

[00:48:35]So zinc plus copper sulfate. So zinc copperate copper because zinc is more reactive.

[00:48:45]Zinc more reactive than copper. So zinc it will displace copper from copper sulfate and it forms zinc sulfate and copper. zinc sulfate and copper pa. So this is nothing but a displacement reaction. This is nothing but a displacement reaction. Okay.

[00:49:11]Okay.

[00:49:19]Zinc sulfate is colorless.

[00:49:27]Okay.

[00:49:31]Okay.

[00:49:32]We'll go for next. We'll go. [laughter] We'll go for the next. Okay.

[00:49:46]Yes.

[00:50:08]Okay.

[00:50:14]Okay.

[00:50:19]A shining metal A shining metal M on burning gives a dazzling white flame and changes to white powder. Identify M already.

[00:50:29]So magnesium.

[00:50:33]So that is burn.

[00:50:38]So this is magnesium and this is magnesium oxide. Okay. Magnesium and magnesium oxide. Represent the above reaction in the form of a balanced chemical equation. Okay. So magnesium in oxygen react to give magnesium oxide. So the balanced equation. So magnesium magnesium oxygen oxygen. So two magnesium oxide. So this equation is balanced.

[00:51:04]This equation is balanced.

[00:51:07]Balanced this equation is balanced.

[00:51:15]Okay. So does M under oxidation or reduction in this reaction? So magnesium magnesium.

[00:51:29]So magnesium magnesium oxide. So magnesium got oxidized.

[00:51:37]Magnesium oxidizes oxidiz. Okay. So magnesium got oxidized.

[00:51:45]Okay. So okay the question in the electrolyis of wateris of water name the gases liberated at the anode and cathode very important electrolyis of water.

[00:52:05]Okay. So this is nothing but an electrolytic decomposition reaction decompose and oxygen gas.

[00:52:20]Okay. So now this is balance. Okay.

[00:52:27]Okay. So 2 is to1 ratio.

[00:52:31]So hydrogen gas.

[00:52:38]Okay. So hydrogen gas oxygen. Okay. Hydrogen is collected at cathode and oxygen is collected at anode. Why is it that the volume of gas collected on the one electro is two times that on the other electro. Okay.

[00:53:08]Double the volume for compared to the oxygen.

[00:53:13]This is to balance the equation.

[00:53:16]Reactants should be equal to the products number of elements in the same.

[00:53:21]Okay. So water is composed of two atoms of hydrogen and one atom of oxygen.

[00:53:26]Therefore amount of hydrogen is double that of oxygen. Okay. So double the volume.

[00:53:42]So the two electrods collect hydrogen and oxygen separately. Therefore volume of gas collected in one electrode is double the volume of gas collected in the other electrode. So volume of hydrogen is to volume of oxygen 2.

[00:54:03]What would happen if dilute H2S4 is not added to waterfuric acid to increase the conductivity of the electrolyte?

[00:54:27]Okay. Pure water is a very very bad conductor. Pure water.

[00:54:34]So pure water.

[00:54:46]Okay.

[00:54:48]1 g of copper powder was taken in a china dish and heated. What change take place is on eating when hydrogen gas is passed over the seat substances. A visible change is seen it. Give the chemical equation of reaction. name and color of the products form of copper powder copper powdery copper oxide which is a black powder.

[00:55:15]Okay.

[00:55:22]Okay. What is the type of reaction? So copper copper oxide. So this is an oxidation reaction. This is a oxidation reaction.

[00:55:33]Okay. This is an oxidation reaction.

[00:55:37]Hydrogen gas is passed over this heated substance.

[00:55:43]Okay. A visible change is seen it.

[00:55:52]So this is a redux reaction. This is a redux reaction. Okay. And copper oxide got reduced to copper. So reduction reaction.

[00:56:10]Okay.

[00:56:20]Next. A compound A is used in the manufacturer of cement. Compu of cement when dissolved in water it evolves a large amount of heat and forms compound B. Compound A is used in the manufactur of cement. Cement manufacturing A is used in the manufacturment.

[00:57:03]When dissolved in water, it evolves a large amount of heat and forms compound.

[00:57:10]Okay. So, A is nothing but calcium oxide. Okay. Calcium oxide.

[00:57:21]calcium hydroxide.

[00:57:24]Okay. It evolves a large amount of heat.

[00:57:26]Okay.

[00:57:33]Okay.

[00:57:40]So, calcium oxide when it is reacting with water it forms calcium hydroxide.

[00:57:44]So, this is nothing but quick lime.

[00:57:49]And this is clay line.

[00:57:52]Okay.

[00:57:55]Okay. Yes.

[00:57:58]Write a chemical equation for the reaction of a water. Calcium oxide.

[00:58:03]Calcium oxide plus H2O gives calcium hydroxide plus hydrogen.

[00:58:23]Okay, list two types of reaction in which this reaction may be classified. Okay, so two types of reaction in which this reaction may be classified. So type of reaction.

[00:58:34]So this is the combination reaction.

[00:58:52]two types of reaction. So this is nothing but this is nothing but a combination reaction and heat energy exothermic reaction. Okay. Next question. Identify the type of each of the following reaction. Also write a balanced chemical equation. A reaction in which reaction mixture becomes warm.

[00:59:17]calcium oxide plus hydrogen water gives calcium hydroxide plus heat.

[00:59:23]So reaction mixture because heat energy is getting released.

[00:59:28]A reaction in which insoluble substances form double reaction.

[00:59:37]Okay.

[00:59:38]So, berium chloride plus magnesium sulfate gives berium sulfate plus magnesium chloride. Okay? Okay. Clear?

[00:59:49]Clear.

[00:59:54]Lead nitrate solution is added to a test tube containing potassium hydrate. Lead nitrate. [clears throat] Lead nitrate solution is added to a test tube containing potassium iodide.

[01:00:07]form name the type of reaction form K3 plus lead diodide.

[01:00:18]Okay. So balance.

[01:00:22]Okay. So this is balanced. So this is nothing but a double displacement reaction.

[01:00:30]Mutual exchange of ions. So this is a double displacement reaction.

[01:00:36]Double displacement reaction balanced equation.

[01:00:40]This is a balanced chemical equation.

[01:00:44]Okay. Write the name and color of the compound precipitated.

[01:00:48]Okay.

[01:01:01]Will be yellow in color.

[01:01:12]clear.

[01:01:15]Yes. Yes. Yes. Yes.

[01:01:23]Okay.

[01:01:30]Yes. So we are done with the chemical reactions and equations. Chemical reactions and equation maximum different types of questions reaction displacement double displacement reactivity series redux reaction. Okay, oxidation reduction and color changes.

[01:01:58]Next chapter next biology.

[01:02:05]So chemical reaction reaction.

[01:02:26]Yes.

[01:02:29]Questioncess.

[01:02:32]Desert plants take up which gas at night and prepare an intermediate which is acted upon by the energy absorbed during the day. Desert plants and prepare an intermediate which is acted upon by the energy absorbed during the day. Come on.

[01:02:49]Come on. This is an easy questioncess.

[01:02:59]Okay.

[01:03:05]Come on.

[01:03:11]Okay.

[01:03:15]Bases and salts.

[01:03:18]So desert plants and prepare an intermediate which is acted upon by the energy absorbed during the day. Come on. Desert plants. Desert plants.

[01:03:33]Desert plants take up which gas at night and prepare an intermediate which is acted upon by the energy absorbed during the day. Okay. So plants plants carbon dioxide plants.

[01:03:55]So carbon dioxide carbon dioxide dioxide intermediate product intermediate So plants.

[01:04:34]So desert plants take up carbon dioxide at the night. Okay. The question, which of the following organisms does not show a parasitic mode of nutrition? Parasitic mode of nutrition. examples.

[01:04:52]Which of the following organisms does not show a parasitic mode of nutrition?

[01:04:56]Cuscuita, ticks, orchids, parramium.

[01:05:02]Okay. Parasitic mode of nutrition.

[01:05:04]Parasitic mode of nutrition.

[01:05:13]Okay. So okay parameium already parramium and that under goes any type of nutrition holoic mode of nutrition.

[01:05:33]So option D is the right answer parasitic mode of nutrition.

[01:05:39]Option D correct answer.

[01:05:42]The enzyme trison acts on which of the following? Very important question.

[01:05:46]Enzyme.

[01:05:52]Okay. So enzyme trison acts on which of the following? Enzyme trson acts on which of the following? Come on. Come on. Enzyme trson. Fats it will be converted into fatty acid with the help of bile juice. carbohydrates, lipids. Okay, so the enzyme acts on which of the following? Proteins.

[01:06:16]Very good. Okay, so enzyme acts on proteins to form amino acid. The question, the respiratory pigment hemoglobin has a very high affinity for which gas? Respiratory pigment.

[01:06:29]Hemoglobin respirator.

[01:06:40]Okay.

[01:06:43]Respiratory.

[01:06:51]It has a very high affinity for carbon monoxide gas.

[01:06:59]But carbon monoxide gas.

[01:07:03]Okay. It should not take question valve is present between dash.

[01:07:10]Okay.

[01:07:13]Okay.

[01:07:17]Okay. So bicuspit wallve. Okay. Okay.

[01:07:23]Okay. So, right atrium and right ventricle left atrium and left ventricle. Okay. Bicaspid valve.

[01:07:33]Buspicid valve is present between left atrium and left ventricle. Okay. Heart.

[01:07:48]Right atrium, right ventricle. This is left atrium. This is left ventricle.

[01:07:54]Okay.

[01:08:07]Which is the right answer? Pulmonary arteria. Option A is the right answer bypro.

[01:08:16]Okay.

[01:08:18]The question.

[01:08:20]When a few drops of iodine solution are added to rice water, the solution turns blue black in color. This indicates that rice water contains dash. Okay.

[01:08:40]indicates.

[01:08:44]So what is that? Okay. Now water means rice water contains starch.

[01:08:56]Okay. Starch testing test. Okay.

[01:09:00]Question. Chemicals present in tobacco smoke lead to the breakdown of the elastic tissue in the alvoli.

[01:09:07]Name the specific condition.

[01:09:10]Tobacco elastic tissues in the specific condition. What do we call what do we call the specific condition as? Come on.

[01:09:27]Come on. Come on. Come on.

[01:09:39]called as M5 SEMA. This is called as M5 SEMA. Okay. Which of the following option shows the transport of oxygen to the cell correctly? Another transport of oxygen to the cell. Transport of oxygen to the cell.

[01:09:54]Okay. Lungs at oxygenated blood.

[01:10:06]This is right atrium. Right. Left atrium. Oxygenated blood.

[01:10:11]Oxygenated blood.

[01:10:17]Left vent. Oxygenated blood through iota.

[01:10:21]Iota body.

[01:10:31]Okay.

[01:10:36]Deoxxyated blood.

[01:10:38]oxygenated blood. So oxygenated bloodminary deoxyminary body. So option A is the right answer.

[01:11:06]Okay.

[01:11:08]The question which of the following events in the mouth cavity will be affected if saliva is lacking in the saliva starch breaking down into sugars.

[01:11:25]Proteins breaking down into amino acid.

[01:11:27]Absorption of vitamins. Fats breaking down into fatty acids and glycerol. Come on. Aa starch breaking down into sugars.

[01:11:35]Okay. So starch vitamins fat.

[01:11:43]Okay. So saliva is related with sugars, carbohydrates. So starch breaking down into sugars in the process when it will get it will be getting affected.

[01:11:55]The question which part of nephron allows the selective reabsorption of useful substances like glucose, amino acids, salt and water into the blood capillaries like glucose amino acids reabsorb.

[01:12:32]capsule.

[01:12:34]Okay.

[01:12:37]Okay.

[01:12:49]selective reabsorption. So option A is the right answer. Option A answer. Next question. In which chamber of heart is oxygenated and deoxxygenated blood form?

[01:13:01]Okay. Oxygenated blood deoxxygenated blood.

[01:13:08]Right atrium, right ventricle.

[01:13:12]Deoxxygenated bladder, left atrium, left ventricle, oxygenated blood.

[01:13:22]Okay. Okay. Clear. Name the various factors which affect the rate of photosynthesis. Very important. Okay.

[01:13:31]Factors affecting the rate of photosynthesis.

[01:13:35]Okay. So, rate of photosynthesis.

[01:13:41]So in the photosynthesis what are the factors light okay light water temperature and carbon dioxide light water temperature and carbon dioxide okay in the factors it affects the rate of photosynthesis okay photosynthesis.

[01:14:15]What are the end products of aerobic respiration? Okay. Aerobic respiration.

[01:14:21]Aerobic respiration.

[01:14:24]Carbon dioxide, water and energy. Either way, anorobic respiration.

[01:14:32]Muscle cells. Anorobic respirationactic acid.

[01:14:39]Anorobic respiration.

[01:14:49]What do you mean by parisic movement?

[01:14:52]What do you mean by parisaltic movement?

[01:14:54]Parisic movement.

[01:14:57]What do you mean by parisaltic movement?

[01:14:59]Okay. So, number Number two contract and relax.

[01:15:30]Okay. So the contraction and expansion of movements of the walls of esophagus.

[01:15:36]The contraction and expansion of movements of the walls of esophagus is called parisaltic movement. In the movement, this movement pushes the foot in a forward direction in the elementary canal.

[01:15:51]Clear question. Give any two functions of stomata. Two functions of stomata.

[01:15:58]Very important. What are the two functions of stomata? Okay, first stomata the pores present on the leaf green parts of the leaf.

[01:16:09]So carbon dioxide.

[01:16:15]Okay. So gasous exchange in respiration.

[01:16:32]So loss of water in the form of vapors.

[01:16:37]So transpiration also is a process of transpiration is a function of stomata.

[01:16:44]Okay.

[01:16:46]Clear?

[01:16:48]Yes. Yes.

[01:16:54]Okay. Question what process are considered essential for maintaining life? Okay. So what are the process required?

[01:17:05]Nutrition, respiration, transportation, excretion and response to stimuli. Okay.

[01:17:11]Next question. The breathing cycle is rhythmic whereas the gaseous exchanges continuous process. Justify the statement.

[01:17:22]The breathing cycle is rhythmic whereas the gaseous exchange is a continuous process. Breathing cycle breathing gas exchange.

[01:17:36]Okay. So breathing inhalation and exhalation process of air. Okay. Breathing cycle.

[01:17:46]Okay. So inhalation diaphragm and exhalation volume and diaphragm dome shape. Okay.

[01:18:07]So alternate expansion and contraction of thoracic cavity breathing. So it is a rhythmic process and exchange of gas is a continuous process as it takes place between the blood and each every cell by diffusion. Okay. So in the breathing cycle contraction and relaxation of this thoracic cavity. Okay. So breathing.

[01:18:38]So there is a movement contraction just by diffusion that's just by diffusion contraction relaxation.

[01:19:06]So this is a continuous process whereas breathing cycle process clear.

[01:19:17]Yes.

[01:19:20]Why do herbivores have longer small intestines than carnivores? Very important question.

[01:19:27]Longer smaller than carnivores longer small intest.

[01:19:39]Why do herbivores have longer small intestines than carnivores?

[01:19:52]Outer layer is made up of cellulose.

[01:20:02]Absorption process. It takes time.

[01:20:12]Cellulose is difficult to digest.

[01:20:15]Cellulose is difficult to digest and takes a longer time for complete digestion.

[01:20:21]Okay.

[01:20:25]Okay. It takes longer time for complete digestion. So need a longer small intestine. Okay.

[01:20:34]Okay, just cell membrane. So meat is easier to digest and h and carnivores and tigers have shorter small intestine.

[01:20:42]Pura at the question, name the glands present in the wall of the stomach that release secretions for the digestion of food. Okay.

[01:20:56]Okay. And what are right the three components of secretion that are released by these glands? Very important. Okay. So I have gastric glands gastric glands. These glands secrete gastric juices in the in the glands gastric juice which contain dilute hydrochloric acid, mucus and two protein digesting enzyme renine and pepsin.

[01:21:33]hydrochloric acid and protein digesting enzyme and pepsino.

[01:21:45]Yes.

[01:21:50]Clear. So gastric juice.

[01:21:54]How does the small intestine absorb digested food? Okay. Small intestine.

[01:21:59]digested absorb very important. So the inner small innermost layer innermost layer finger projection layer finger like projections.

[01:22:19]We call this as viing projections to increase the surface area for absorption. Absorption surface area.

[01:22:35]Okay.

[01:22:40]I have blood capillaries. These will also comprise blood capillaries to aid in the absorption of simple molecules.

[01:22:48]Okay. So, so absorbed foods.

[01:23:02]Okay. Clear. Yes. Clear.

[01:23:08]What advantages does a terrestrial organism have over an aquatic organism in obtaining oxygen for respiration?

[01:23:15]Respiration.

[01:23:17]organisms organisms.

[01:23:23]Okay. So the amount of oxygen in air so amount of oxygen compared to the amount of oxygen present in water present in water. So the amount of oxygen in air you know the amount of oxygen in air is more than the amount of uh dissolved oxygen in the water. So dissolved oxygen aquatic organisms.

[01:23:54]Okay. So oxygen oxygen.

[01:24:04]Okay.

[01:24:07]Okay.

[01:24:19]It should put lot of efforts. Okay.

[01:24:23]How is food transported in plants? Okay.

[01:24:31]That is nothing but okay. So the food is transported by phium to the plant parts like root, fruit, seed and growing regions. Okay.

[01:24:43]What do we call transllocation?

[01:24:47]What do we call this? Is called as transllocation. Okay. So in the flow se tubes are present which together with companion cell transllocate food in upward and downward direction.

[01:25:04]So tubes. So together with companions so transported in both the way food is transported in birectional way describe the structure of nephron with functioning. Okay very very important very very important. Okay. So structure of nephron.

[01:25:40]Okay. So nephron nephron is the structural and functional unit of kidney. Okay. Nephron structural and functional unit of kidney. Okay. So glowman's capsule tubules and loop of henley.

[01:25:56]Okay. Socess excess fluid.

[01:26:14]It also regulates blood pressure, electrolyte balance and blood pH.

[01:26:18]electrolyte balance and blood pH and blood pressure.

[01:26:25]How do plants get rid of excy products?

[01:26:28]Plants products. How will it get rid of? Plants get rid of oxygen and carbon dioxide.

[01:26:54]Plants oxygen and carbon dioxide diffusion through.

[01:27:03]Okay. And old leaves, old branches.

[01:27:11]Okay. They are shed off. old leaves, old branches.

[01:27:17]Plants have a mechanism by which the roots release waste products. Okay.

[01:27:37]That is also a kind of waste product kind of waste product.

[01:27:46]How is the amount of urine produced regulated?

[01:27:49]Amount of urine produced.

[01:27:54]Okay. [snorts] So the kidney can reabsorb water from the filtrate.

[01:28:02]Okay. So kidney water excess amount of water. So excess amount of water.

[01:28:42]reabsorb.

[01:28:43]Okay. So, urine concentrated.

[01:28:47]Okay. So, this mechanism depends upon the amount of water left in the body and the filtrate. The relative water concentration signals the brain based on whether water is reabsorbed or released.

[01:28:58]So, this is how the kidney regulate urine formation. Okay.

[01:29:03]Okay.

[01:29:06]Yes.

[01:29:12]Explain the cause of cramps after excessive physical exercise. Excessive physical exercise.

[01:29:33]some amount of energy but excessive physical exercise normal amount of energy amount of energy amount of energy. So muscles anorobic respiration muscles it will provide extra energy.

[01:30:09]Okay. So muscles is broken down into lactic acid.

[01:30:14]Anorobic respiration break.

[01:30:31]So during excessive physical exercise the demand of energy is high but the supply of oxygen to produce energy is limited. So exercise that is called as muscle cramps. Okay.

[01:31:01]So the accumulation of lactic acid causes muscle cramps.

[01:31:06]at the question in a single-sellled organism diffusion is sufficient to meet all the requirements of food gas exchange and waste removal but it is not the case in multisellular organisms explain the reason for this difference okay nutrition respiration diffusion process multisellular organisms.

[01:31:49]So in a single reason so single organism there is no specific organ related to food intake, gas exchange or waste removal. Okay.

[01:32:00]So single gas and single cell direct contact.

[01:32:20]Okay.

[01:32:26]Okay. So direct contact with the environment single cell organism organism the skin cells directly interact with the environment. Okay.

[01:32:36]Diffusion is a slow process.

[01:32:46]Diffusion is a slow process that takes a very long time to reach all body parts and it is insufficient to meet oxygen requirements. Okay. So diffusion slow process. Okay.

[01:33:07]diffusion diffusion process.

[01:33:17]It takes a very long time.

[01:33:27]How do guard cells open and close tomato pores? Okay, so open sorry.

[01:33:39]How is it?

[01:33:40]Okay.

[01:33:46]Okay.

[01:33:55]Will become sw.

[01:34:06]Okay.

[01:34:16]God cells will become flaccid will become and close.

[01:34:34]Yeah, this is how opening and closing of stomata is done by gessa.

[01:34:41]All plants give out oxygen during day and carbon dioxide during night. Give out give reason. All plants day oxygen are released and night carbon dioxide.

[01:35:00]Night carbon dioxide, morning oxygen release. What is the reason? Okay, so respiration occurs throughout the day and night but photosynthesis occurs only during the day. Respiration oxygen respiration.

[01:35:17]So oxygen respiration photos.

[01:35:42]Okay.

[01:35:44]So during the day plants give out oxygen. carbon dioxide.

[01:35:49]Okay. A byproduct of photosynthesis and respiration throughout the day. Okay. So only because one of the most integral components needed for life. So [snorts] during the day plants give out oxygen a byproduct of photosynthesis. Thus plants give carbon dioxide during the night time when there is no photosynthesis. So oxygen a byproduct of photosynthesis. Okay. and sorry differentiate between autorophic and heterotrophic nutrition. Okay. So process okay nutrition organism does not depend on other organism for its food. Okay nutrition organisms cannot prepare food and depends on other organism for food.

[01:37:01]Okay. Heterotrophic organism.

[01:37:07]So it depends on other organism for food. So organic material is prepared from inorganic materials. Autorophic nutrition carbon dioxide, water, sunlight. Inorganic materials. Organic material like glucose is prepared in the presence of sunlight.

[01:37:26]Organic material cannot be prepared from inorganic materials.

[01:37:30]Nutrition. Autorophic nutrition. Example green plants. Herotrophic nutrition example.

[01:37:40]Animus.

[01:37:43]Okay.

[01:37:46]Next question. Why? What is double circulation in humans? Mention its importance. Okay. So, double circulation.

[01:37:56]This is lungs, either heart, body cells.

[01:38:03]Okay. So body cells deoxxygenated blood cells deoxxygenated blood oxygenated oxygen oxygenated body.

[01:38:28]Okay. So complete cycle it is traveling twice. Okay. First heart.

[01:38:55]Okay. So this is called as double circulation. Humans have double circulation as the blood passes twice through the heart in one complete cycle.

[01:39:03]Pulmonary circulation circulation right ventricle lungs deoxxygenated blood.

[01:39:15]Okay. and lungs pulmonary pulmonary circulation. Okay.

[01:39:23]And next systemic circulation importated.

[01:39:38]Okay. So there is no mixing between oxygenated and deoxxated. Okay.

[01:39:43]Oxygen supply efficient body temperature.

[01:39:50]Last question. Three kinds of cells present in blood and write one function of each. Okay. What are the three kinds of blood blood cells? Red blood cells, white blood cells and platelets. Red blood cells function. Red blood cells and hemoglobin. Hemoglobin.

[01:40:10]Hemoglobin it transports oxygen from the lungs to the body cells and take carbon dioxide from the body cells and pass it to the lungs. So red blood cells it helps in the gaseous transport defenses. Okay.

[01:40:32]Antibodies platelets these are responsible for blood clotting during injuries platelets.

[01:40:54]Platelets.

[01:40:56]What are the three events that occur during photosynthesis? Very important biology.

[01:41:03]Very good. Very good.

[01:41:06]Uh three events that occur in photosynthesis light energy absorb with the help of chlorophyll. Next light energy is converted into chemical energy water hydrogen and oxygen. And third reduction of carbon dioxide to carbohydrates.

[01:41:22]Okay. So we are done with life process.

[01:41:33]Okay, next we'll go for light chapter.

[01:41:48]Okay, we'll go for light chapter.

[01:41:54]Okay, light refraction and refraction.

[01:41:57]Okay, max.

[01:42:01]So, next chapter we'll go for the light chapter.

[01:42:06]Okay, first question. First question, a sperical mirror.

[01:42:16]Okay, a sperical mirror and a thin lens have each focal length of minus 20 cm.

[01:42:22]Okay, a sperical mirror and a thin lens.

[01:42:26]Okay, spherical mirror and a thin lens have each focal length of minus 20 m.

[01:42:30]Okay, both are concave. Both are convex.

[01:42:35]Mirror is concave. Lens is convex.

[01:42:38]Mirror is convex. Lens is concave. Which is the right answer?

[01:42:43]Come on.

[01:42:48]Come on. Come on. Come on.

[01:43:01]Okay.

[01:43:02]Good news.

[01:43:04]Okay. So, spherical mirror and thin lens have each of focal length of minus 20 cm. Okay. So minus 20 convex mirror.

[01:43:37]So focal length is here. So this is this side is negative. So mirror focal. So that is a concave mirror.

[01:43:52]Okay. So this is side is negative.

[01:44:01]So focal length will be positive on the same side. Yeah. So focal length is negative. So focal negative both are concave. Option A correct answer. Okay.

[01:44:20]The question. A student traces the path of a ray of white light through a rectangular glass lamp and marks the angle of incidence, refraction and emergence as shown. Okay. Okay.

[01:44:34]Which angle or angles have no have not been marked correct correctly.

[01:44:49]So mark.

[01:44:52]So this is angle of this is angle of refraction. Correct.

[01:44:58]This is angle of refraction. Correct.

[01:45:00]This is angle of emergence.

[01:45:06]angle of emergence.

[01:45:17]Angle of incidence of emergence.

[01:45:23]So which is marked incorrectly?

[01:45:27]Angle incidence and angle of emergence.

[01:45:30]So option D is the right answer.

[01:45:33]The question in which of the following is a concave mirror used [cough] in which of the following concave mirror is used? Come on.

[01:45:52]Fuel size image of distant tall building. Safety mirror in shopping mall. Rear view mirror in vehicles.

[01:45:58]Convex mirror cooker. I use concave mirror. I use concave mirror.

[01:46:10]Okay. Okay.

[01:46:13]Question.

[01:46:16]Array of light. Array of light starting from air passes through medium A. Array of light starting from air passes through medium A. medium B and medium C with refractive indexes over medium refractive index. If this ray emerges out in air from sea okay then for which pair of media is the bending of light rarer to dense denser bending it will be towards the normal denser to air bending will be away from the normal. So which pair of media is the bending of light least?

[01:47:03]A r to a a to b to c and c to error.

[01:47:10]Come on. So air first case rer to denser rer to denser towards the normal and next a to b. Okay. So 1.50 50A and next 1.33. So a it is more refractive index is more okay refractive index and speed of light is inversely proportional.

[01:47:42]Refractive index and speed of light is refractive index speed of light.

[01:47:51]Okay. Speed of refractive index speed of light.

[01:47:58]Okay. Which means that is little more dense.

[01:48:03]Okay. So, A to B denser to rarer. Denser to rarer.

[01:48:12]B to C 1.33 2.42.

[01:48:17]So refractive index.

[01:48:21]So speed of refractive ind.

[01:48:25]Okay. So it is like rarer to denser.

[01:48:31]Okay.

[01:48:40]This is denser and air. So denser to rare.

[01:48:46]Okay. for so rare to denser to complet different different exactly different medium and B to C reference indiffract.

[01:49:21]Okay.

[01:49:26]Refractive index difference. So bending will be least.

[01:49:36]Okay. So bending will be least in the B Aract.

[01:49:45]Okay. If a lens converges the sun rays at a point 20 cm away from its optical center, the power of the lens converges the sunray converges the sunray at a 20 cm away from its optical center. So infinity.

[01:50:06]Okay. So 20 cm is nothing but the focus.

[01:50:10]So f is equal to 20 cm and f is + 20 cm.

[01:50:16]Okay. Okay. What is the power of the lens? 1 by f. So 1 by 20.

[01:50:24]1x 20 now.

[01:50:28]1x 20 means what is the answer? What is the answer?

[01:50:42]Okay. So, plus five opted is the right answer.

[01:51:00]Okay.

[01:51:02]Okay. Clear.

[01:51:05]Clear.

[01:51:10]A mirror produces a real inverted and highly enlarged image. The real image inverted image and highly enlarged image in the real image.

[01:51:23]Inverted image and highly enlarged image mirror.

[01:51:31]A mirror produces a real inverted and highly enlarged image. So invertave.

[01:51:45][clears throat] So this is a concave mirror. This is a concave mirror. Clear.

[01:51:58]Maybe concave or convex. Convex mirror.

[01:52:02]Virtual and direct. Convex mirror.

[01:52:06]virtual you can't say it is a convex mirror.

[01:52:10]Okay, that is a concave mirror.

[01:52:16]Yes.

[01:52:20]Okay. The question can we go for the next question?

[01:52:28]Yes. Yes. Yes.

[01:52:38]Yes.

[01:52:41]Question. We'll go for the next question. Magnification produced by a rear view mirror fitted in vehicles.

[01:52:49]Magnification produced by a rear view mirror. Magnification produced by a rear view mirror fitted in vehicles.

[01:53:03]magnification.

[01:53:06]Someone magnific it will be less than one.

[01:53:27]So it is less than one. Okay. Okay.

[01:53:33]Okay. Okay. So assertion and reasoning when we'll go for this refractive index of water is 4x3 and that of glass is 3x2 with respect to air. What is the refractive index of glass with respect to water? Okay. So refractive index of water in a 4x3 refractive index of gas in a 3x2. A refractive index of glass the glass with respect to water. Okay.

[01:54:04]Which is equal to refractive index of grass with respect to water. So refractive index of gas divided by refractive index of water. Okay. So 3x2 / 4x3 which is equal to 9 by 8 refractive index of glass with respect to water.

[01:54:22]Distinguish between real and virtual image. Very important question.

[01:54:30]A real image can be caught on a screen.

[01:54:52]project screen. So it is caught on a screen. The image is caught on a screen.

[01:54:57]So that is the real image. PL is virtual. A real image can be caught on a screen whereas a virtual image cannot be caught on a screen. Real image is always invert.

[01:55:12]And virtual image is always erectual.

[01:55:20]Okay.

[01:55:24]Okay. Real images form when the rays of light after reflection or refraction actually meet at some point. Okay. So real after reflection.

[01:55:42]So actual meeting of virtual image is formed when the rays of light after reflection or reflection appear to meet at a point. Okay.

[01:55:57]reflected but it appears to meet.

[01:56:06]Okay. Real image can be formed. Okay.

[01:56:10]Okay.

[01:56:12]Name the type of mirror used in the following situation. Headlights of car headlights concave mirror.

[01:56:20]Okay. And rear view mirror of vehicles.

[01:56:24]We use convex mirror. Okay. Diminished image and wider angle.

[01:56:30]Next question.

[01:56:32]Refractive index of alcohol and tarpentine oil with respect to air or 1.36 and 1.47. Find the refractive index of tarpentine oil with respect to alcohol. In which of the two media will the speed of light be more? Okay. So, refractive index speed of light in vacuum to the speed of light in medium.

[01:56:53]So refractive index of alcohol 1.36 refractive indent 1.77 1.77.

[01:57:04]So refractive index of tarpentine with respect to alcohol.

[01:57:10]Refractive index of tarpentine oil divided by refractive index of alcohol.

[01:57:15]Okay. Now 1.47 by 1.36 which is equal to 1.08. the refractive index of tarpentine oil with respect to alcohol. Okay. Okay.

[01:57:30]In which of the two meds proportional refractive indely proportional. So refractive index indractive index of light. The speed of light will be more in alcohol than next question. Two thin lenses thin lenses of focal length 20 cm and 25 cm are placed in contact. Okay. What is the effective power of the combination of the lenses combined combin already power of the lens is additive.

[01:58:33]So power.

[01:58:36]Okay. So focal length.

[01:58:40]Okay. So total focal length.

[01:58:47]So 1x 20x 25 1x f. So total focal length 1x f_sub_1 plus 1x f_sub_2. So f_sub_1 20 f_sub_2.

[01:58:59]So 1x 20 + 1x 25 100 by 9. Okay. So 9 by 100. So focal length 100 by 9 which is 1 by 9 m. Okay. So effective power is 1x.

[01:59:17]So 1 by 9 is equal to power.

[01:59:22]Okay.

[01:59:26]Okay. numerical type of question a 6 cm object a 6 cm object height of the object 6 cm is placed perpendicular to the principal axis of a convex lens convex lens a focal length 15 cm okay so focal length is 15 cm so focus is here so focal length is positive. The distance of the object from the lens object distance 10 cm. So object so it is minus 10.

[02:00:08]Okay. Find the position size and nature of the image form.

[02:00:13]Now position of the image.

[02:00:16]Okay. Position of the image using the lens formula. Lens formula 1x f= 1x v - 1x u 1x f= 1x v - 1x u okay position size and nature of the image position of the image formula 1 f= 1 v - 1 by uage Next is the nature of the image.

[02:00:54]The nature of the image magnific Hdash in the image size H into the object size. Okay.

[02:01:14]V by U= Val is nothing but 6 cm. So height of the image height of the image is 18 cm. So image distance already image height 18 cm and image formed is virtual erect and magnified object size 6 cm image size 18 cm. So this is enlarged. Okay. And magnification is positive here.

[02:01:56]Okay. So image formed is virtual, erect and enlarged.

[02:02:02]Okay. So numerical problems numeric problems.

[02:02:13]Okay.

[02:02:18]Next question. A students wants to another a student wants to project the image of a candle flame on a screen 90 cm in front of a mirror. A student wants to project the image of a candle flame on a screen 90 cm in front of a mirror.

[02:02:34]Okay. So object distance 90 cm negative keeping the flame at a distance 15 cm from its pole.

[02:02:51]Okay.

[02:02:55]A student wants to project the image of a candle flame on a screen 90 cm in front of a mirror. Okay.

[02:03:03]90 cm.

[02:03:05]Okay. By keeping the flame at a distance of 50 cm from it. Okay. So object 15.

[02:03:22]Okay.

[02:03:33]So concave mirror should be used. Okay.

[02:03:37]Determine the linear magnification in this case. Okay.

[02:03:41]Object distance. So m is equal to minus v by u. So minus if v is also negative and m is equal to minus v by u. Okay. Sous vative vus.

[02:04:11]Okay. and u1 the -5 cancel which is equal to -6.

[02:04:20]The magnification is -6 linear magnification.

[02:04:26]Find the distance between the object and its image.

[02:04:30]What is the distance? Okay. So object distance which is nothing but 75 cm.

[02:04:50]draw diagram to show the image for in this case. Okay.

[02:04:56]Okay. So inverted image 15.

[02:05:06]Okay. Okay.

[02:05:10]At a distance of 90 cm from the mirror.

[02:05:14]Distance of 90 cm from the mirror.

[02:05:20]Okay. And the image should be real and inverted and inverted.

[02:05:29]So in the candle in the image, what is the distance between them? 75 cm.

[02:05:37]Okay. Clear?

[02:05:40]Okay. So next concave lens has a focal length of 15mave lens. So f is nothing but negative. F is negative.

[02:06:06]What distance should the object be placed from the lens so that it forms an image at 10 cm? So image distance 10 cm.

[02:06:20]Okay. and magnificus 30 cm. So objectification so mal by u m is equal to v by u m is equal to v by u so v - 10 cm v - 30 cm so 1x 3 so plus 0.33 plus 0.33 so the positive sign The image is direct and virtual and image is one/ird of the size of the object.

[02:07:24]So very easy.

[02:07:32]Okay. So chemical reactions and equations in the chapter next light chapter.

[02:07:47]Next life process chapter in the moon chapter important questions.

[02:07:55]I hope so everything is clear.

[02:07:57]Everything is clear. So homework just questions.

[02:08:10]Okay.

[02:08:18]Okay.

[02:08:25]Sessions. Okay.

[02:08:31]All the very best and thank you so much.

[02:08:34]Thank you and all the best. Bye-bye.