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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 55101. |
prove f=r/2 |
| Answer» | |
| 55102. |
What is doberneir triad |
Answer» According to Dobereiner, all elements occurred in groups of three, when arranged in increasing order of atomic masses. He referred to these groups as triads. In a traid the elements had similar chemical properties. Traids of the Dobereiners classification:\xa0Traid1:\t Element Atomic mass Lithium (Li) 7 Sodium (Na) 23 Potassium (K) 39\tTraid2:\t Element Atomic mass Chlorine (Cl) 35.5 Bromine (Br) 80 Iodine (I) 127\tTraid3:\t Element Atomic mass Calcium (Ca) 40 Strontium (Sr) 88 Barium (Ba) 137\tDobereiner’s law\xa0of triads\xa0states that, the\xa0atomic mass\xa0of the middle element of a triad is the\xa0arithmetic mean\xa0of the atomic masses of the other two elements. Example:\xa0In\xa0the triad of lithium, sodium and potassium.\xa0The atomic mass of lithium is 7 and the atomic mass of potassium is 39. The average of masses of lithium and potassium gives atomic mass of sodium 23. Drawbacks:\xa0All the\xa0known elements\xa0could not be arranged in the form of triads.\xa0This law did not hold good for elements with\xa0very low or very high atomic mass. Example: The arithmetic mean of the atomic masses of fluorine 19 and bromine 80, which comes to 49.5, varies significantly from the atomic mass of chlorine, which is 35.5.\xa0 |
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| 55103. |
Who discover neutron |
| Answer» James Chadwick in 1932 | |
| 55104. |
List two unisexual flowers |
| Answer» Coconut and papaya flower | |
| 55105. |
Why do we rub magnesium ribbon with sand paper before burning |
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Answer» In order to remove the oxide layer formed on the surface of magnesium .......... We rub magnesium ribbon with sandpaper before burning remove the protective layer from the surface of magnesium ibbon.That protective layer is magnesium carbonate. To remove the layer of magnesium oxide formed by the action air on it |
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| 55106. |
Why plants do photosynthesis |
| Answer» PHOTOSYNTHESIS. Unlike animals, most plants do not need to find food, because they can make it for themselves. Plants use energy from sunlight to turn water and carbon dioxide into an energy-rich sugar called glucose. This process is called photosynthesis, which means “making things with light”. | |
| 55107. |
1.write the chemical equationIn electicity water is passed through brine solution. |
| Answer» NaCl+H20---------> NaOH+H2 +Cl2(Brine sol.)(Electrolysis)(h2gas)(cl2 gas) | |
| 55108. |
Please tell me the one practical of chapter metal and nonmetal |
| Answer» | |
| 55109. |
How to know room temperature |
| Answer» Room temperature are the normal temperature of the any elementsIts normally 22degree | |
| 55110. |
What are isotopes..?? In short explain.. |
| Answer» The atoms which posses same atomic number (the atoms same element) but different mass numbers are called Isotopes. The difference in mass number is due to difference in number of neutrons present in the nucleus.Hydrogen : ₁H¹,₁H², ₁H³ | |
| 55111. |
What is magnetic field lines ? |
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Answer» Magnetic fieldlines are lines.which are surrounded by bar magnet.magnetic fieldlines direction is from north seek to south seek..where seek means poles..& they are closed and curve lines surrounding by bar magnet..like The direction..as we know that..that\'s it..yaar, mere ko ethna hi patha h..bhai?..i think it will help u.. The lines around magnet |
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| 55112. |
This time the question paper will set up from ncert |
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Answer» Is it truth? No yaar..from CBSE.. |
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| 55113. |
Why oil containing unsaturated fatty acids should be chosen for cooking? |
| Answer» Oils are unsaturated carbon compounds. So they have double or triple bonds. Double and triple bonds are easy to be digested or to be broken down into simpler substances. But if a saturated compounds like vanaspati Ghee are used. It becomes difficult for our body to digest the food as single bonds are not easily broken down into simpler substances by the acids present in our body. This results in incomplete digestion, which is not good for our health. | |
| 55114. |
What is difference between calcination,chlorination,catanation |
| Answer» 1.Calcination is the process of heating of carbonate ores in limited or absence of oxygen into metal oxides.2.if the hydrogen atoms of a hydrocarbon takes place by chlorine, it is called chlorination.3. The self linking property of carbon to form long chains and branches, this is known as catanation. | |
| 55115. |
Which book is best for board exam before 2 months from the exam |
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Answer» Exam idea ? Evergreen + all in one for sst evergreen book series Mtg books |
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| 55116. |
How coal was formed |
| Answer» Coal was formed by the decomposition of plants and animals burried under the earth millians of years ago | |
| 55117. |
What is the electrolyte used |
| Answer» An electrolyte is a substance that contains free ions and behaves as an electrically conductive medium. Electrolytes generally consist of ions in solution, they are also known as ionic solutions. A strong electrolyte is one where many ions are present in the solution and a weak electrolyte is one where few ions are present. Strong electrolytes are good conductors of electricity and weak electrolytes are weak conductors of electricity. | |
| 55118. |
Why is ethanol used in making of tincture iodine, cough syrup, tonic etc. |
| Answer» Ethanol is a\xa0solvent used to make tincture of Iodine because the cell membrane of microorganisms is made up of lipids and ethanol is a the solvent, which can dissolve the lipid of easily and kill the micro-organisms that may be pathogenic. | |
| 55119. |
Why variation is benificial to the species but not necessary for indivisiable |
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Answer» Variations are\xa0beneficial for the survival of the species.\xa0Populations of organisms fill well-defined places, or niches, in the ecosystem, using their ability to reproduce. However, niches can change because of reasons beyond the control of the organisms and could even wipe out the entire population.\xa0However, if some variations were to be present in a few individuals in these populations, there would be some chance for them to survive.For example - If there were a population of bacteria living in temperate waters and suppose the water temperature were to be increased by global warming. Most of these bacteria would die, but the few heat resistant variants\xa0would survive and grow further. Variation is thus useful for the survival of species over time.\xa0 Oti |
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| 55120. |
Name the substances which on addition to acetic acid produce carbon dioxide gas. |
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Answer» Sodium hydrogen carbonate on reaction with acetic acid releases carbon dioxide gas.NaHCO3\xa0+ CH3COOH → CH3COONa + H2O + CO2\xa0 Reaction with sodium carbonate and sodium bicarbonate |
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| 55121. |
Why are compounds of carbon are considered as poor conductor of electricity |
| Answer» Graphite is an interesting material, an allotrope of carbon (as is diamond). It displays properties of both metals, and nonmetals. However, like a metal, graphite is a very good conductor of electricity due to the mobility of the electrons in its outer valence shells | |
| 55122. |
Name the substance form by alcohol in presence of air |
| Answer» Yeast | |
| 55123. |
Why in addition reaction use Alkene akyne |
| Answer» Reactions of Alkenes and Alkynes. Alkenes and alkynes are generally more reactive than alkanes due to the electron density available in their pi bonds. In particular, these molecules can participate in a variety of addition reactions and can be used in polymer formation. | |
| 55124. |
What are halides |
| Answer» Halides are binary compounds that are of which one part is an element another part is the halogen atom. A radical is less electronegative compared to that of halogens which form astatine, bromide, fluoride and chloride. Most of the salts are halides. Various halide compounds are tested using silver nitrate solution. Some include Kl, KBr, and KCl. | |
| 55125. |
Nitrogen is an inert gaseous non metal . Explain |
| Answer» Nitrogen is found as a diatomic molecule (N2) in nature. There is a triple bond between the two nitrogen atoms. The triple bond is pretty strong. Therefore, it needs a lot of energy to break those bonds and participate in a reaction. So nitrogen is commonly referred to as and used as an inert gas (high abundance & low cost.) However, it’s not truly inert like most noble gases. Nitrogen does react if the conditions are met. But those conditions are not exactly mild, but are not as extreme as for noble gases. | |
| 55126. |
Why alchohol is considered to be versatile in natute |
| Answer» The versatile nature of carbon due to the presence of covalent bond enables it to form a large number of compounds.(i) Carbon due to its property of catenation possesses a unique ability to form bonds with other atoms of carbon, giving rise to large number of molecules and compounds having long chains of carbon, branched chains of carbon or carbon atoms arranged in rings and linked by single, double or triple bonds.(ii) Carbon being tetravalent is capable of bonding with four other atoms of carbon or any other combining mono-valent element.\xa0(iii) Carbon forms compounds with oxygen (Carbon-dioxide), hydrogen (Methane), nitrogen (Hydrogen cyanide), sulphur, chlorine (Chloromethane) and many other elements giving rise to compounds with specific properties depending upon the elements present in the compound.\xa0 | |
| 55127. |
Explain micelles which is a part of soap??????? |
| Answer» Micelles:\xa0A micelle is an aggregate of surfactant molecules dispersed in a liquid colloid. A typical micelle in aqueous solution forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single tail regions in the micelle centre. | |
| 55128. |
Why carbon share electron ??????? |
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Answer» Because its valency is 4 and it had 4 electons in its outermost shell Karbonn shares electron because it doesn\'t make ionic bond it only make covalent bond if it gives 4 electrons then it requires a large amount of energy and nucleus doesn\'t have a much energy and if it games for electrons then it is hard for the nucleus to accommodate all the 10 electrons The elements having less than 8 electrons in their outermost shell always have a tendency to attain an octet in order to attain a noble gas configuration by gaining or losing electron forming ionic compounds. In case of carbon with atomic number 6 there are four electrons in its outermost shell due to which it is termed as tetravalent. It gains or loses four electrons to attain the nearest noble gas configuration. |
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| 55129. |
What is the principal of Mendeleav periodic table? |
| Answer» Dmitri Ivanovich Mendeleev, a Russian scientist arranged the elements in increasing order of their relative atomic masses. He was honoured with Noble prize in 1906 for his Periodic Table.Mendeleev’s Periodic Law states that the properties of elements are the periodic function of their relative atomic masses.Mendeleev arranged all 63 elements; which were discovered till his time; in the order of their increasing relative atomic masses in a tabular form. It is known as Mendeleev’s Periodic Table. He divided the table in eight columns and seven rows. The columns are known as groups and rows are known as periods. | |
| 55130. |
Explain endothermic and exothermic reaction |
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Answer» The reaction in which energy is released in the form of heat, light and electricity is called exothermic reaction. The reaction in which energy is absorbed in the form of heat, light and electricity is called endothermic reaction. The chemical reaction in which heat is given out is known as exothermic reaction.Ex:-magnesium oxide + water = magnesium hydroxide. In this reaction a lot of heat is produced ,enough to give boles on hand.This reaction in simple language is the reaction between choona and water. The reaction in which the product formed has low temperature than the reactactants is called endothermic reaction.Eg sodium chloride + water = sodium hydroxide + hydrochloric acid. In dimple language the reaction between salt and water is an endothermic reaction. If you try then dont touch the product in exothermic but you can touch the product in endothermic.Thank you. Those reaction in which heat is evolved is called exothermic reaction and those reaction in which heat is absorbed is called endothermic reaction |
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| 55131. |
What is the process of nephron |
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Answer» Thanks sir Nephron is the structural and functional unit of kidney. It is a basic filtering unit of kidney. It is a long coiled tubule whose one end is connected to the double wall cup shaped structure called bowman\'s capsule and other end to a urine collecting duct. Bowman\'s capsule containes a number of blood capillaries known as glomerulus that is followed by the tubular part of nephron which forms loops at some places. Glomerulus filters the blood that passes through it. It also ensures to remove only harmful chemicals. It absorbs nutrients and water. The other waste is passes out from the body through urethra in the fgorm of urine. Kidney has a structural and functional unit called nephron. Each kidney consists of millions of nephron which plays a significant role in the filtration and purification of blood. The nephron is divided into two portions, namely, the glomerulus and the renal tubule. The glomerulus is constituted of capillaries of the renal artery. The Bowman’s capsule, proximal convoluted tubule (PCT), Henle’s loop, distal convoluted tubule (DCT) and collecting duct, all together form the tubules of the kidney (renal tubule). It is a part of kidney . So it will refine the waste which will come in last.??????? |
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| 55132. |
Can I get notes of physics for pre boards.... |
| Answer» Ya, get it from this app only | |
| 55133. |
Classify into acidic oxides and basic oxides . Na2O,So4,Mgo,Co2 |
| Answer» An acidic oxide is an oxide which when combined with water gives off an acid.A basic oxide is an oxide which when combined with water gives off a base.Acidic oxides - SO4 ,CO2\xa0.Basic oxides Na2O, MgO | |
| 55134. |
Why respiration is called as exothermic reaction |
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Answer» Respiration is considered as exothermic reaction because when we intake food and the food undergoes during digestion the food is converted into simpler substances glucose and this glucose reacts with oxygen present in our body cells and provides us energy Respiration considered to be exothermic because in this food burn to produce energy and (in exothermic energy is evolved or produce) |
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| 55135. |
how to prepare science full syllabus in 10days for pre board examination.tell me |
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Answer» Revise your notes and solve the ncert book questions which helps you to prepare perfectly. Go in your examination with full confidence you will surely get good marks. Just fully revised the textbook and solve sample paper which are given at official site of cbse |
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| 55136. |
Difference between quick lime and slaked lime |
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Answer» Slaked lime is chemically calcium hydroxide, and its chemical formula is Ca(OH)2. It is a white coloured solid which is obtained when water is added to calcium oxide (CaO).CaO + H2O → Ca(OH)2Lime water on the other hand is a saturated solution of slaked lime in water. Quick lime (CaO) and slaked lime (Ca[OH]2).When quick lime react with carbon dioxide is converted into calcium carbonate CACO3.WHEN WE GET HEAT TO SLAKED LIME IT CONVERTED INTO QUICK LIME+WATER |
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| 55137. |
How will the message reach an organ if there is no neuron in it? |
| Answer» The messge will not be transmitted if there is no neuron in it. This is for multiple cell organisms. If there is unicellular organisms there is no need for neuron becase there is only one cell.? | |
| 55138. |
What is the advantage of tendrils for plants? Is there anything except climbing |
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Answer» The key is to provide a thin enough support for the leaf stem to curl around. But thanks for ur ans Except this anything else For providing support to the plant |
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| 55139. |
Focal length 12 cm , distance10 and find object distane |
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Answer» Is it a lens or a mirror concave or convex 1/f = 1/12= 1/u + 1/v = 1/10+ 1/v 1/v= 1/12-1/101/v= 5-6/601/v= -1/60V= -60cm Distance of what |
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| 55140. |
What is the difference between Heredity and Inheritance? |
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Answer» Heredity is the phenomenon of passing traits from parent to offspring. Sperms and eggs are the gametes produced by reproductive organs of male and females. These are haploid with one set of chromosomes.??????Inheritance:The passing of genetic information from parent to child is known as inheritance.The information is in chemical codes carried by deoxyribonucleic acid (DNA ) in the *** cells (eggs and sperms)☺️☺️☺️☺️☺️☺️☺️ Both you acquire from your parent. They mean the same thing. |
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| 55141. |
Why fries fly grow at night? |
| Answer» Fireflies glow at night because they have a special protein which undergoes oxidation and they are able to glow at night | |
| 55142. |
Why are carbon and its compounds are poor conductors of electricity |
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Answer» they are poor conductor as they are nonmetal except graphite it is a good conductor of electricity because they are electronagetive |
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| 55143. |
Why white coloured Agcl turns grey when kept in sunlight? |
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Answer» Because of Photolytic decomposition, AgCl>Ag+Cl2 Because agcl decomposes into silver and chlorine also by photolytic decomposition reaction |
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| 55144. |
Why glucose do not conduct electricity |
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Answer» Inheritance:The passing of genetic information from parent to child is known as inheritance.The information is in chemical codes carried by deoxyribonucleic acid (DNA ) in the *** cells (eggs and sperms)??????? Ions have the ability to carry electricity . However glucose does not release H+ions in presence of water . Hence, glucose does not condut electricity. Because glucose contain of only h + ions but it doesn\'t ionizes fully in water |
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| 55145. |
Twinkling of stars ? |
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Answer» 1. The star light goes under atmospheric refraction before reaching the earths surface.2. The atmosphere is made up of particles oc dust, smoke, water droplets and air molecules. Hence the starlight travels from rearer medium to denser madium.3. Thus the apparent position of star is alightly upward than its actual position.4. Also, the stars are point sized sources of light which are located far away from earth. Hence the stars appear to be twinkling. Because stars are far away from earth and due to atmospheric refraction that twinkles and as we know our Earth is not stationery When earth moves atmosphere also changes and there will be changed in its refractive index also It\'s principle is atmospheric refraction ? |
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| 55146. |
What is stimulus in bio |
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Answer» Any disturbance either external or internal is called stimulus Any quick change around us which district or attention from one thing to that thing this is known as stimulus The sudden change in environment is called stimulus |
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| 55147. |
What is s e x hormone |
| Answer» Testosterone – This is the main *** hormone present in men which cause puberty, muscle mass growth, and strength, increases bone density and handles facial hair growth.Estrogen-This is the main *** hormone present in women which cause puberty, prepares the uterus and body for pregnancy and even regulates the menstrual cycle. Estrogen level changes during menopause because of which women experience many uncomfortable symptoms.Progesterone – This hormone is replicated to estrogen but is not taken as the main *** hormone. It helps in maintaining menstrual cycle and also assist in pregnancy like estrogen does. | |
| 55148. |
Characteristics of group |
| Answer» Kaunsa group | |
| 55149. |
Do All transparent body disperse light? |
| Answer» No ,because some of the transparent material has not a plain surface such as glass turtle | |
| 55150. |
Why Gregor Mendel is know as father of genetics ? |
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Answer» Gregor Mendel, the father of modern genetics, presents his research on experiments in plant hybridization. Becoz he was the first person to discover genes and its DNA through pea plants. |
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