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myCBSEguide, , Class 09 - Science, Term-2 Sample Paper - 01, , Maximum Marks: 40, Time Allowed: 2 hours, , General Instructions:, i. All questions are compulsory., ii. The question paper has three sections and 15 questions. All questions are compulsory., iii. Section–A has 7 questions of 2 marks each; Section–B has 6 questions of 3 marks each; and Section–C has 2, case-based questions of 4 marks each., iv. Internal choices have been provided in some questions. A student has to attempt only one of the, alternatives in such questions., Section A, 1. Define the terms:a. Atomic number, b. Mass number, 2. Avinash can run at a speed of 8 ms-1 against the frictional force of 10 N, and Kapil can move at a speed of 3, ms-1 against the frictional force of 25 N. Who is more powerful and why?, To practice more questions & prepare well for exams, download myCBSEguide App. It provides complete, study material for CBSE, NCERT, JEE (main), NEET-UG and NDA exams. Teachers can use Examin8 App to, create similar papers with their own name and logo., 3. A ball is thrown vertically upwards. The speed of the ball was 10m/s when it had reached one half of its, maximum height., i. How high does the ball rise?Take g= 10ms2, ii. Find the velocity and acceleration 1s after it is thrown., 4. A ball is dropped from the jumping board of a swimming pool, which is at a height of 20 m. A second ball is, thrown from the same board after one second with initial velocity u. If both the balls hit the water together,, calculate the initial velocity of second ball. Do they hit the ground at the same time? (Take g = 10 ms-2), 5. The signs and symptoms of a disease will depend on the tissue or organ which the microbe targets Justify, the statement with two examples., OR, A doctor/nurse/health-worker is exposed to more sick people than others in the community. Find out how, she/he avoids getting sick herself/himself., 6. An automobile engine propels a 1,000 kg car A along a levelled road at a speed of 36 km h-1. Find the power, if the opposing frictional force is 100 N. Now, suppose after travelling a distance of 200 m, this car collides, with another stationary car B of same mass and comes to rest. Let its engine also stop at the same time., Now car B starts moving on the same level road without getting its engine started. Find the speed of the car, B just after the collision., OR, Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 1/8

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myCBSEguide, , 7., , i. What is meant by potential energy of a body?, ii. A body of mass m is raised to a vertical height h through two different paths A and B., What will be the potential energy of the body in the two cases? Give reason for your answer., i. Seema buys few grains of gold at the poles as per the instruction of one of her friends. She hands over, the same when she meets her at the equator. Will the friend agree with the weight of gold bought?, If no, why?, ii. If the moon attracts the earth, then why does the earth not move towards the moon?, OR, A test tube is loaded with lead shots so that it floats in a liquid immersed to a mark on the tube. The total, weight of tube and lead shots is 30 gf. The tube is then placed in water and lead shots are added to sink the, tube to the same mark. Now, the tube and lead shots weigh 35 gf. Calculate the relative density of liquid., Section B, , 8. Calculate the following quantities in 5.6g of nitrogen. [Atomic mass of N = 14 u], i. Number of moles of N2, ii. Number of molecules of N2, iii. Number of atoms of nitrogen, 9. Study the data given below and answer the questions which follow:, Particle, , Electrons, , Protons, , Neutrons, , A, , 2, , 3, , 4, , B, , 10, , 9, , 8, , C, , 8, , 8, , 8, , D, , 8, , 8, , 10, , i. Write the mass number and atomic number of particles A, B, C, D., ii. Which particles represent a pair of isotopes? Explain., OR, (i) State the method of determining the valency of an element if its number is given., (ii) Determine the valency of the following elements, the atomic number which are given in parenthesis:, Chlorine (17), Sulphur (16), Aluminium (13), 10. Write the symptoms when following organs are targeted by microbes., a. Lungs, b. Liver, c. Brain, 11. In the following table, the mass numbers and the atomic numbers of certain elements are given., Element, , A, , B, , C, , D, , E, , Mass no., , 1, , 7, , 14, , 40, , 40, , At. no., , 1, , 3, , 17, , 18, , 20, , Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 2/8

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myCBSEguide, i. Select a pair of isobars from the above table., ii. What would be the valency of element C listed in the above table?, iii. Which two sub-atomic particles are equal in number in a neutral atom?, 12. What are the limitations of Rutherford's model of the atom?, OR, In a gold - foil experiment :, a) Why did many, , - particles pass through the gold foil undeflected?, , b) Why did few, , - particles deflect through small angles?, , c) Why did few, , - particles, after striking the gold foil, retrace their path?, , 13. Explain giving reasons –, (a) Balanced diet is necessary for maintaining health body., (b) Health of an organism depends upon the surrounding environmental conditions., Section C, 14. Sulfur dioxide is a colorless gas with a pungent odor. It is a liquid when under pressure, and it dissolves in, water very easily. Sulfur dioxide in the air comes mainly from activities such as the burning of coal and oil, at power plants or from copper smelting. In nature, sulfur dioxide can be released into the air from, volcanic eruptions., 'SO2 is an air pollutant released during the burning of fossil fuels and from automobile exhaust'., To practice more questions & prepare well for exams, download myCBSEguide App. It provides complete, study material for CBSE, NCERT, JEE (main), NEET-UG and NDA exams. Teachers can use Examin8 App to, create similar papers with their own name and logo., i. Write the names of elements present in this gas., ii. What are the valencies of sulphur in SO2 and SO3?, iii. Find out the number of molecules in 5 moles of SO2., iv. Calculate the number of moles in 320 g of SO2 gas., OR, v. Calculate the molar mass of 10 moles of sodium sulphite., [Given, atomic masses of S = 32 u, O = 16 u, Na = 23 u and NA = 6.022, , 1023 per mol], , 15. In physics, work is the energy transferred to or from an object via the application of force along with a, displacement. In its simplest form, it is often represented as the product of force and displacement. A force, is said to do positive work if (when applied) it has a component in the direction of the displacement of the, point of application. A force does negative work if it has a component opposite to the direction of the, displacement at the point of application of the force., , i. State the law of conservation of energy., ii. Define mechanical energy., iii. Calculate the energy in kWh consumed in 5 hours by four devices of power 600 W each., , Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 3/8

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myCBSEguide, Class 09 - Science, Term-2 Sample Paper - 01, , Solution, Section A, 1., , a. Atomic Number is defined as the total number of protons present in one atom of an element.It is, denoted by the letter Z. The atomic number of element = Number of protons in one atom, of an element., b. The mass number is defined as the total number of protons and neutrons present in one atom of, an element.It is denoted by the letter A. Mass number = No. of protons + No. of neutrons, , 2. Power of Avinash PA = FA . vA = 10, Power of Kapil PK = FK. vK = 25, , 8 = 80 W, , 3 = 75 W, , So, Avinash is more powerful than Kapil., To practice more questions & prepare well for exams, download myCBSEguide App. It provides, complete study material for CBSE, NCERT, JEE (main), NEET-UG and NDA exams. Teachers can, use Examin8 App to create similar papers with their own name and logo., 3. Let the initial velocity = u, Let the maximum height reached = h m, When it reached , the velocity = 10m/s, Now, , When the ball reaches the highest point, v = 0, , Height = 10 m, Maximum height reached = 10m, , Initial velocity of the ball when it was thrown up = 14.14 m/s., Velocity after 1s, , Acceleration after 1s = -10m/s2, 4. Case (i) = For the first ball, Initial velocity (u) = 0, Final velocity (v) = ?, Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 4/8

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myCBSEguide, Acceleration due to gravity (g) = 10 ms-2, Distance of fall (S) = 20 m, Time of fall (t) = ?, Using, , we have time of fall of the first ball, , Since the second ball is thrown 1 second later. Therefore for the two balls to reach the ground at the, same time, the second ball should in motion for t = 2 - 1 = 1 second, Therefore using the equation, , we have, , 5. Every microorganism shows its effect on any particular tissue or organ after entering into the body., Thus, there is a change in the structure and function of the tissue or organ. For example, if the lungs, are the targets, the symptoms will be cough and breathlessness. If the liver is the target, there will be, jaundice. This is called Organs specific manifestation., OR, The following steps are taken by the doctors/nurses to avoid getting sick themselves:, i. Immunisation., ii. Wearing gloves and masks., iii. Taking proteinaceous food to enhance their immunity., iv. Taking prophylactic medicines., v. Disposing the blood samples, sputum, etc. safely., 6. mA = mB = 1000 kg. v = 36 km/h= 10 m/s, Frictional force = 100 N, Since, the car A moves with a uniform speed, it means that the engine of car applies a force equal to the, frictional force., Power =, =, =100 N × 10 m/s = 1000 W, after collision,, m A u A + m Bu E = m A υ A + m B, 1000 × 10 + 1000 × 0 = 1000 × 0 + 1000 ×υB, vB = 10 ms-1., OR, , 7., , i. Energy possessed due to the position of a body is called potential energy., ii. The work done against gravity in both cases is mgh. It is independent of the path along which the, body is moved and it depends only on the initial and final positions of the body., i. No, her friend will not agree with the weight of gold bought because weight at poles is greater than, the weight at equator., , Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 5/8

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myCBSEguide, ii. We know that the gravitational force is always attractive, still, the moon does not fall on the earth, because the gravitational force between the earth and the moon works as the necessary centripetal, force for the moon to make it revolve around the earth., OR, Weight of displaced liquid = Weight of the tube and lead shots = 30 gf, Weight of water displaced for same volume, = Weight of the tube and lead shots in 2nd case = 35 gf, Now RD =, , = 0.857, , To practice more questions & prepare well for exams, download myCBSEguide App. It provides, complete study material for CBSE, NCERT, JEE (main), NEET-UG and NDA exams. Teachers can, use Examin8 App to create similar papers with their own name and logo., Section B, 8. Atomic mass of nitrogen = 14 u, Molar mass of N2 = 2, 14 = 28 g/mol, i. Number of moles of, =, ii. Number of molecules of, , Avogadro's number =, , = 1.2044, 1023 molecules, iii. One molecule of N2 contains two atoms of nitrogen., Number of atoms of nitrogen, =2, Number of N2 molecules, =2, 9., , 1.2044, , 1023 = 2.4088, , 1023, , i., Particle, , Atomic number, , Mass number, , A, , 3, , 3+4=7, , B, , 9, , 9 + 8 = 17, , C, , 8, , 8 + 8 = 16, , D, , 8, , 8 + 10 = 18, , ii. Particles C and D as they have same number of protons, i.e. same atomic number but different, mass number., OR, (i) The number of electrons gained, lost or shared to form an octet of electrons in the outermost shell,, gives us the combining capacity of an element. The combining capacity of each atom to form molecules, is called its valency. The atomic number gives the number of electrons in the outermost (valence) shell., If the number of valence electrons is less than 5, the number of valence electrons is the valency of the, element. If the number of outermost electrons is 5 or more, the number of valence electrons is, subtracted from 8 to get the valency of the element., Valency = Number of valence electrons (for 4 or lesser valence electrons), Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 6/8

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myCBSEguide, Valency = 8 - Number of valence electrons (for more than 4 valence electrons), (ii) The valency of the given elements is as follows:-, , 10., , Elements, , Atomic no., , Electronic Configuration, , Valency, , Chlorine, , 17, , 2, 8, 7, , -1, , Sulphur, , 16, , 2, 8, 6, , -2, , Aluminium, , 13, , 2, 8, 3, , +3, , a., b., c., i., , Lungs - cough, breathlessness, Liver - jaundice, Brain - headache, vomiting, fits., 11., D and E have the same mass number but different atomic numbers. Hence, they are a pair of, isobars., ii. Electronic configuration of C is 2(K), 5(L). Hence, its valency is three because it gains three, electrons to attain a stable electronic configuration., iii. For a neutral atom, Number of electrons = Number of protons, Thus, electrons and protons are equal in numbers in a neutral atom., 12. Limitations of Rutherford's model of atom:, (i) According to classical electromagnetic theory, a charged particle such as an electron moving under, the influence of attractive electrostatic forces would lose energy continuously in the form of radiation., As a result of this, the electrons should lose energy and would move in even smaller orbits, ultimately, falling into the nucleus. But the collapse of electrons into the nucleus does not occur. There is no, explanation for this behaviour in the Rutherford's model of atom., (ii) Rutherford did not specify the number of orbits in an atom and the number of electrons in each, orbit., OR, An alpha particle is identical to the nucleus of a helium atom. Alpha decay is a radioactive process in, which a particle with two neutrons and two protons is ejected from the nucleus of a radioactive atom., a) Many, , – particle passed through the gold foil undeflected. This shows that most of the space inside, , an atom is empty., b) Few, – particles deflected through small angles. This shows that there is a positive charge at the, centre of the gold atom. (Repulsion of positively-charged aplha particles), c) Few, – particles after striking the gold foil retraced their path. (Strong repulsion of positivelcharged aplha particles). This shows that all the positive charge is concentrated in a very small volume, inside an atom. This concentration of positive charge was called the nucleus., 13. (a) Balanced diet contain all the nutrient required for maintaining proper health as well as needed for, growth and repair. Lack of single nutrient causes deficiency diseases., (b) surrounding environmental conditions plays an important role in the maintenance of health. For ex, we feel depressed if –, (i) surrounding are dirty or polluted, (ii) garbage is not collected or disposed off, (iii) drains are not cleaned and water collects in the streets or open spaces. Unclean surrounding causes, Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 7/8

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myCBSEguide, the entry of germs via air, water, food or vectors and makes the person unhealthy., To practice more questions & prepare well for exams, download myCBSEguide App. It provides, complete study material for CBSE, NCERT, JEE (main), NEET-UG and NDA exams. Teachers can, use Examin8 App to create similar papers with their own name and logo., Section C, 14., , i. Sulphur and oxygen., ii. Valency of sulphur in SO2 = 4, Valency of sulphur in SO3 = 6, iii. 5, , Avogadros number = 5, , 6.022, , 1023, , = 3.011, 1023 molecules, iv. m = 320 g, Molar mass (m) of, SO2 = 32 + 2, 16 = 64 g/mol, = 5 moles, v. Molar mass of 10 moles of Na2SO3, 15., , = 10 [23, 2 + 32 +16, 3] = 1260 g, i. Law of conservation of energy: The energy in a system can neither be created nor destroyed., It may be transformed from one form to another, but the total energy of the system remains, constant., ii. The energy possessed by a body due to a displacement caused in it by the application of a force is, called mechanical energy., iii. Energy = Power, , Time = 4, , 600 W, , 5h, , 12 KWh, , Hence the energy in kWh consumed is 12 kWh., , Copyright © myCBSEguide.com. Mass distribution in any mode is strictly prohibited., , 8/8