SAMPLE PAPER : PHYSICS: CLASS XI

 

Class-XI

Time-3hrs                                                                                                                        Total Martks-70

 

 

SECTION A

Attempt the following questions.                                                                                               1x20 = 20

1.       Can the sum of two vectors be a scalar?                                                                                                    

2.       What is the angle between the vectors A x B & B x A?                                                                             

3.       Why does the direction of motion of a projectile become horizontal at the highest point of its trajectory?          

4.       What are horizontal and vertical components of acceleration of a body thrown horizontally with uniform speed?               

5.       Find the dimensional formulae of (i) Charge (ii) potential  

6.       Express one micron to meter.

7.       Slope of the velocity time graph is called ____________.

8.       Can a body have uniform speed but still accelerating?

9.       What is centripetal force?

10.    Write two differences between speed and velocity.

11.    What is the trajectory of a projectile?

12.    What is momentum?

13.    What is angle of friction?

14.    What is static friction?

15.    What is angular momentum?

16.    Explain the radius of gyration.

17.    What is potential energy?

18.    What is a conservative force?

19.    What is an elastic collision?

20.    Explain coefficient of restitution.                                                                                                                                                                                                                                                                                                                                                               

SECTION B

Attempt the following questions.                                                                                       2x9 =18

21.    Explain Newton’s Second Law.

22.    Explain inertia and its types.

23.    What is a torque?

24.    Can the sum of two vectors be a scalar?  Explain.

25.    Determine unit vector which is perpendicular to both A=2i + j + k and B =I – j + 2k?    

26.    If unit vectors A and B are inclined at an angle θ, then Prove that unit vector|A−B|= 2sin                   

27.    Show that the average K.E of a gas molecule is directly proportional to the temperature of the gas? 

28.    State four assumptions on which kinetic theory of gas is based?  

29.    A projectile is fired horizontally with a velocity u. Show that its trajectory is a parabola.

        Attempt the following questions.                                                                                   3x8= 24

30.    A bullet of mass 0.04 kg moving with a speed of 90 m/s enters a heavy wooden block and is stopped after a distance of 60 cm. What is average resistive force exerted by the block on the bullet?

31.    Derive an expression for the kinetic energy of a body.

32.    If the linear momentum of a body increases by 20%, what will be the % increase of the kinetic energy of the body?

33.    What is the principle of conservation of linear momentum?

34.    Write the expressions of parallel axes theorem and perpendicular axes theorem.

35.    Derive the relation between Torque and angular momentum.

36.    Calculate  for hydrogen at 27⁰C                                                                                                                    

(a) K.E.of one gram mole of gas

(b) K.E. of one gram of the gas

(c) root mean square velocity of molecule. Molecular weight of hydrogen=2 gram.

37.    A cricket ball is thrown at a speed of 28m/s in a direction 30° above the horizontal. Calculate

         (a) maximum height              

  (b) the time taken by the ball to return to the same level.  

         (c) the horizontal distance from the thrower to the point where the ball returns to the same level.

 

SECTION C

Attempt the following questions.                                                                 2x4 =8

 

38.    Prove that in an elastic one-dimensional collision between two bodies, the velocity of approach is equal to the velocity of separation after the collision. Hence derive expressions for the velocities of the two bodies in terms of their initial velocities before collision.

39.    Briefly explain how is a horse able to pull a cart.

THE FUNCTIONALITY MICROSOFT STREAM

Microsoft Stream is a video-sharing service developed by Microsoft that allows users to upload, view, and share videos with others within their organization. It is a cloud-based platform that is designed to help organizations securely manage and distribute video content.

The functionality of Microsoft Stream can be broken down into several key features, including:

Video creation and upload: Users can upload videos from their computer or mobile device, or create and record new videos directly within the platform. Videos can be edited, trimmed, and enhanced with captions, transcripts, and annotations.

Video sharing and collaboration: Microsoft Stream makes it easy to share videos with others within an organization. Users can share videos via links, embed them in websites or applications, or share them directly within Microsoft Teams or other Microsoft applications. Users can also collaborate on videos by commenting, tagging, and discussing them with others.

Video discovery and search: Microsoft Stream allows users to search for videos using keywords, titles, and descriptions. Users can also discover new videos by browsing categories, channels, and playlists.

Video security and permissions: Microsoft Stream provides robust security and permissions controls to ensure that videos are only accessible to authorized users. Administrators can control who can upload, view, and share videos, and can set permissions at the individual video level.

Analytics and reporting: Microsoft Stream provides detailed analytics and reporting on video usage, including views, engagement, and completion rates. This information can be used to optimize video content and improve engagement.

Overall, Microsoft Stream is a powerful tool for managing and sharing video content within an organization. Its ease of use, collaboration features, and security controls make it a popular choice for businesses of all sizes that want to use video to communicate and engage with employees, customers, and partners.

FUNCTIONALITY OF MICROSOFT FORMS

Microsoft Forms is an application developed by Microsoft that allows users to create and distribute surveys, quizzes, and polls. It is a cloud-based service that allows users to create and share custom forms with others, and collect data from respondents.

The functionality of Microsoft Forms can be broken down into several key features, including:

Form creation: Microsoft Forms makes it easy to create professional-looking forms and surveys. Users can choose from a variety of pre-made templates, or create their own custom form from scratch. Forms can include multiple types of questions such as multiple-choice, text input, rating, and Likert scales.

Form sharing: Once a form is created, users can easily share it with others. Forms can be shared via email, link, QR code, or embedded directly into a website. Users can also set permissions for who can respond to the form.

Data collection and analysis: As responses come in, Microsoft Forms automatically collects and aggregates the data into charts and graphs, making it easy to analyze and understand the results. Users can export the data to Excel for further analysis or to integrate with other tools.

Collaboration: Microsoft Forms allows multiple users to collaborate on a form, making it easy to work on projects together. Users can share forms with others for editing and collaboration, and can leave comments and feedback for each other.

Integration with other Microsoft products: Microsoft Forms integrates with other Microsoft products such as Microsoft Teams, OneNote, and Excel, making it easy to incorporate form data into other workflows.

Overall, Microsoft Forms is a powerful tool for creating and distributing surveys, quizzes, and polls. Its ease of use, flexibility, and integration with other Microsoft products make it a popular choice for individuals and organizations of all sizes.

EXCRETION

CLASS X   |    SCIENCE    |    LIFE PROCESSES

      Notes prepared by Subhankar Karmakar

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click to access other class notes

SCIENCE: CLASS X: CBSE (CLASS NOTES)

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• EXCRETION

The process of removal of toxic wastes from our body of an organism is called excretion. Excretion takes place in plants as well as in animals. 

Biochemical reactions that takes place inside the cells of an organism may produce toxic wastes which are removed by the process of excretion. 

• EXCRETION IN PLANTS

• The main waste products produced by plants are carbon dioxide, water vapour and oxygen. 

• The gaseous wastes of respiration and photosynthesis in plants (carbon dioxide, water vapour and oxygen) are removed through the "stomata" in leaves and "lenticels" in stems and released to the air. 

• The plants excrete carbon dioxide produced as a waste during respiration only at night time. 

• The plants excrete oxygen as a waste only during day time. 

• Water vapour produced during respiration is excreted by plants during day time as well as night time by the process of Transpiration. 

• The plants also store some of the waste products in their body parts like in the leaves, bark and fruits of the plants. Plants get rid of them by shedding of leaves, peeling of bark and felling of fruits. 

• Some of the plant wastes get stored in the fruits of the plant in the form of solid raphides. Plants secrete their wastes in the form of gum and resins from their stems and branches. 

• EXCRETION IN ANIMALS

1. AMOEBA: In Amoeba carbon dioxide is removed by diffusion through the cell membrane but nitrogeneous wastes like ammonia and excess water are removed by Conractile Vacuole. 

2. EARTHWORM: In Earthworm, the tubular structures called nephredia are the excretory organs. But it also uses its moist skin as an additional excretory organ. 

• EXCRETION IN HUMAN 

Excretion is the process by which the body eliminates waste products and excess substances to maintain homeostasis, or balance, in the body. In human beings, excretion primarily involves the elimination of metabolic waste products and excess water and salts.

There are several organs involved in excretion in human beings:

Kidneys: The kidneys are the primary excretory organs in the body, responsible for filtering waste products from the blood and excreting them in the form of urine.

Skin: The skin plays a role in excretion by eliminating excess water, salts, and urea through sweat.

Lungs: The lungs excrete carbon dioxide and small amounts of water vapor during exhalation.

Liver: The liver plays a role in excretion by eliminating toxins and waste products from the body.

The process of excretion in human beings involves several steps. First, waste products are filtered from the blood by the kidneys and transported to the bladder. The bladder then stores the urine until it is eliminated from the body through the urethra. Meanwhile, excess water, salts, and urea are eliminated through sweat and the lungs.

Overall, the process of excretion is essential for maintaining the proper balance of fluids and chemicals in the body and for removing waste products that can be harmful if they build up in the bloodstream.

• The Salient Points

1. The major wastes produced by the human body  are : Carbon dioxide and Urea. 

2. Carbon dioxide is producedas a waste by the oxidation of food during the process of respiration and Urea is produced as a waste by the decomposition of unused proteins in the liver. 

3. While Lungs excrete carbon dioxide, our Kidneys excrete urea.

4. The excretory system of human beings consists of (i) two kidneys, (ii) two ureters, (iii) Bladder and (iv) Urethra. 

5. The function of kidneys is to remove the poisonous substance urea, other waste salts, and excess water from the blood and excrete them in the form of a yellowish liquid called urine. 

6. The dirty blood enters the kidneys through the renal artery and cleaned blood is carried away from the kidneys by the renal vein. 

7. Each kidneys are connected to the urinary bladder by excretory tubes called ureters. Urine is stored in the bladder. Urethra is a tube and the urine collected in the bladder is expelled from our body through the urethra. 

8. Each kidney is made up of a large number of excretory units called nephrons. The nephron has a cup shaped bag at its upper end which is called Bowman's Capsule. The lower end of Bowman's capsule is tube shaped and it is called a tubule. The Bowman's capsule and tubule taken together make a nephron. 

9. One end of the tubule is connected to the Bowman's capsule and the other end is connected to a urine collecting duct of the kidney. 

10. The Bowman's capsule contains a bundle of blood capillaries which is called glomerulus. One end of the glomerulus is attached to the renal artery which brings the dirty blood containing urea waste to it. The other end of glomerulus comes out the Bowman's capsule as a blood capillary, surrounds the tubule of nephron and finally joins a renal vein carrying clean blood.

11. The function of glomerulus is to filter the blood passing through it. Only the small molecules of substances like glucose, amino acids, salts, urea and water present in blood can pass through the glomerulus and collect as filtrate in the Bowman's capsule. 

The large molecules like oroteins and blood cells can not pass out through the glomerulus capillaries and hence remain behind in the blood. 

12. The function of the tubules of nephron is to allow the selective reabsorption of the useful substances like glucose, amino acids, salts and water into the blood capillaries. But the waste material like urea remains behind in the tubule. It does not get reabsorbed into blood capillaries. 

LECTURE 7: RESPIRATORY SYSTEM IN HUMANS

HUMAN RESPIRATORY SYSTEM:

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The main organs of human respiratory system are: Nose, Nasal Passage (Nasal Cavity), Trachea, Bronchi, Lungs and Diaphragm.

1. Air for Respiration is drawn into our body through the nostrils (two holes in the nose) present in the nose. This air goes to nasal passage (passage behind the nostrils). 

2. Nasal hair and mucus present in nasal cavity cleans the incoming air. The part of throat between the mouth and wind pipeis called Pharynx. 

3. The wind pipe is known as Trachea. Trachea is reinforced by rings of cartilage, hence it will not collapsedeven when there is no air in it. Upper end of Trachea contains Voice box or Larynx.

4. Trachea is divided into two smaller tubes called. Bronchi. The two bronchi is connected to the two lungs. 

LUNGS: 

5. The lungs lie in the chest cavity or thoracic cavity and separated from abdominal cavity by a muscular partition called diaphragm. The diaphragm is a sheet of muscle below the lungs. It helps in "breathing in" and "breathing out". 

6. The lungs are covered by two thin membranes called pleura and protected by the rib cage made of ribs. 

7. Each bronchus divides in the lungs to form a large number of smaller tubes called bronchioles. 

8. The bronchioles have have tiny air-sacs at their ends called alveoli. The walls of alveoli are very thin and they are surrounded by very thin blood capilaries. Here, oxygen is taken in the body and carbon di oxide is eliminated, i.e. gaseous exchange takes place in alveoli. All the alveoli have a cumulative surface area of around 80 square metres. 

9. Oxygen of air diffuses out from the alveoli walls to the blood and carried by the blood to all the parts of the body and oxygen again diffuses into the individual cells and takes part in the respiration and releases carbon di oxide. 

RATE OF BREATHING

The average breathing rate in an adult man at rest is about 15 to 18 times per minute. The breathing rate increases with increased physical activity. 

HAEMOGLOBIN

Oxygen required for breathing and respiration is carried by haemoglobin present in our blood. The normal range of haemoglobin in the blood of a healthy adult person is from 12 to 18 gm/dL (grams per decilitre) of blood. The deficiency of haemoglobin in the blood of a person reduces the oxygen carrying capacity of blood resulting in breathing problems, tiredness and lack of energy. 

CARBON DI OXIDE POISONING

Haemoglobin has more affinity for carbon monoxide then oxygen. So, if carbon monoxide gas is inhaled by a person then this carbon di oxide binds very strongly with haemoglobin  in the blood and prevents it from carrying oxygen to the brain and other parts of the body and it creates fatal breathing problems. It is known as Carbon dioxide poisoining. 

VENTILATOR

When a patient suffers a serious breathing problem, the patient is put on a machine called "ventilator" in which a tube is inserted directly into the trachea of the patient to help him in breathing comfortably. 

Q&A Exam class 10 Science

1 and 2 mark questions:

Q1. If an object is placed in front of a concave mirror of 20 cm focal length, what is the position of the object when it will give a real and diminished image?

Q2. An object is placed in front of a concave mirror such that its image also formed at the same place at 10 cm in front of the mirror. What is the focal length of the mirror?

Q3. We wish to obtain an erect image of an object using a concave mirror of focal length 15 cm. 

a. What should be the range of distance of the object from the mirror?

b. What is the nature of the image?

Q4. An object is placed in front of a concave mirror such that its image also formed at the same place at 10 cm in front of the mirror. What is the focal length of the mirror?

Q5. At what distance from a concave mirror of focal length 20 cm, should an object 1.5 cm long be placed in order to get an erect image 4.5 cm tall?

Q6. Between which two points of concave mirror should an object be placed to obtain a magnification of m = - 2.

Q7. Why does a concave mirror cannot be used as a rear view mirror in vehicles?

Q8. Two spherical mirrors A and B produce images with linear magnifications + 1.5 and + 0.5 respectively. Identify which one of them is a a convex mirror and why?

Q9. State two effects caused by the refraction of light?

Q10. The refractive index of water with respect to air is 4/3. What is the refractive index of air with respect to water?

Q11. The refractive indices of kerosene, turpentine and water are 1.44, 1.47 and 1.33 respectively. In which of these materials does light travel fastest?

Q12. A virtual, erect and magnified image of an object is to be obtained with a convex lens. For this purpose, where should the object be placed?

Q13. If an object is placed at the centre of curvature in front of a concave lens, what kind of image it will produce?

Q14. A spherical lens has a power of, - 2.5 D. What is the focal length and nature of the lens?

Q15. Explain the spectrum of white light. 

Q16. While passing through a prism, which colour deviates least ?

Q17. Why do the stars always appear to be twinkling?

Q18. What is tyndall effect?

Q19. Why does the sky always appear to be blue?

Q20. Name any two effects of atmospheric refraction.

4 mark questions:

Q21. If the magnification of a mirror is +4,

a. What type of mirror is this?

b. If the focal length of the mirror is 5 cm, what is the the object distance?                 1 + 3

Q22. Draw a diagram to show the refraction of light through a glass prism. On this diagram, mark (i) incident ray, (ii) emergent ray, and (iii) angle of deviation.                             2½ + 1½

Q23.  A virtual image at a distance of 20 cm in front of the lens is produced when an object is placed 100 cm from the lens. Calculate (i) focal length of the lens and (ii) magnification produced. (iii) Also calculate the power of the lens.                                                2 + 1 + 1

Q24. An object is placed at a distance of 6 cm from a convex lens of focal length 4 cm. If the the height of the object is 5 cm, find

(i) position, (ii) nature and (iii) height of the image.                                           2 + 1 + 1

Q25. An object is placed at a distance of 20 cm from a convex mirror of radius of curvature 60 cm. If the the height of the object is 3 cm, find (i) position, (ii) nature and (iii) height of the image.                                          2 + 1 + 1

Q26. A real image of 6 cm height is produced when an object of 2 cm height is placed at a distance of 16 cm from a concave mirror. 

(i) what is the focal length of the mirror?

(ii) find the position of the image?         2 + 2 

LECTURE 3 : TYPES OF CHEMICAL REACTIONS (CLASS X)

TYPES OF CHEMICAL REACTIONS

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There are many types of Chemical reaction. Some of the most important types of Chemical Reaction are:

1. Combination Reaction

2. Decomposition Reaction

3. Displacement Reaction

4. Double Displacement Reaction

5. Oxidation and Reduction Reaction

A. COMBINATION REACTION

Those reactions in which two or more substances combine to form a single substance, are called combination reaction.

Examples: 

1. Burning of Magnesium in air.

2. Formation of water from hydrogen and oxygen.

3. Burning of carbon to form carbon dioxide.

4. Reaction between hydrogen and chlorine to form hydrochloric acid. 

5. Sodium metal burns in chlorine to form sodium chloride.

6. When iron powder is heated with sulphur, iron sulphide is formed. 

7. Calcium oxide reacts vigorously with water to form calcium hydroxide.  

8. Ammonia reacts with hydrogen chloride to form ammonium chloride. 

9. Carbon monoxide reacts with oxygen to form carbon dioxide. 

10. Sulphur dioxide reacts with oxygen to produce sulphur trioxide. 

B. DECOMPOSITION REACTIONS

Those reactions in which a compound splits up into two or more simpler substances are known as decompostion reactions. It always needs energy either in form of heat, light or electricity to carry out a decompostion reaction. 

When a decompostion reaction is carried out by heating, it is called "thermal decomposition". 

Examples. 

1. When calcium carbonate (CaCO₃) is heated, it decomposes to give calcium oxide (CaO) and carbon dioxide (CO₂). (Thermal decomposition)

2. When Potassium chlorate (KClO₃)

is heated in the presence of manganese dioxide catalyst, it decomposes to give potassium chloride (KCl) and oxygen (O₂).  (Thermal decomposition)

3. When ferrous sulphate (green) (FeSO₄) is heated strongly, it decomposes to form ferric oxide (brown) (Fe₂O₃), sulphur dioxide (SO₂) and sulphur trioxide (SO₃).  (Thermal decomposition)

4. When colourless lead nitrate Pb(NO₃)₂ is heated strongly, it breaks down to form simpler substances like yellow lead monoxide PbO, Nitrogen dioxide NO₂ and oxygen O₂.  (Thermal decomposition)

5. When electric current is passed through acidified water, it decomposes to give hydrogen gas and oxygen gas. (Decomposition using electricity)

6. When electric current is passed through molten sodium chloride, it decomposes to give sodium metal and chlorine gas.  (Decomposition using electricity)

7. When electric current is passed through molten aluminium oxide Al₂O₃, it decomposes to give aluminium metal and oxygen gas.  (Decomposition using electricity)

8. When Silver Chloride is exposed to light, it decomposes to form silver metal and chlorine gas. (Decomposition using light energy)

9. When silver bromide (pale yellow) (AgBr) is exposed to light, it decomposes into silver metal (greyish white) and Bromine gas. (Decomposition using light energy). 

Uses of Decomposition Reactions

The decomposition reactions using electricity are used to extract several metals like Aluminium, Sodium from their chlorides or oxides. 

Like when fused or molten metal chlorides or oxides is decomposed by passing electricity, metals are produced in the Cathode (negative electrode). 

Decomposition Reactions in our body

The digestion of food in our body is an example of decomposition reaction. Like complex carbohydrates (starch) decomposes into simple sugar and proteins into amino acids. 

DISPLACEMENT REACTIONS 

Those reactions in which one element takes place of another element in a compound, are known as displacement reactions. 

A more reactive elements always displaces a less reactive element from its compound. 

Metal Reactivity Series

(How to remember reactivity series)

1.  Please.      Potassium

2.  Stop.          Sodium

3.  Calling.      Calcium

4.  Me.             Magnesium

5.  A.                Aluminium

6.  Careless.   Carbon

7.  Zebra.         Zinc

8.  Instead.      Iron

9.  Try.              Tin

10. Learning.   Lead

11. How.          Hydrogen

12. Cow           Copper

13. Saves.       Silver

14. Goat.         Gold

1. As Zinc is more reactive than Copper, When a strip of Zinc metal is placed in Copper sulphate solution, then Zinc displaces Copper and Zinc Sulphate solution and Copper are obtained. 

CuSO₄ (aq) (blue solution) + Zn (s) (silvery white) → ZnSO₄ (aq) (colourless solution) + Cu (s) (red brown)

2. When a piece of Magnesium metal is placed in copper sulphate solution and Copper metal are formed. 

CuSO₄ (aq) (blue solution) + Mg (s) → MgSO₄ (aq) (colourless solution) + Cu (s) (red brown)

As Magnesium is more reactive than Copper.

3. When a piece of Iron metal is placed in Copper Sulphate solution, then Iron (II) Sulphate solution and Copper metal are formed. 

CuSO₄ (aq) (blue solution) + Fe (s) → FeSO₄ (aq) (greenish solution) +  Cu (s) (red brown)

As Iron is more reactive than Copper.

4. When a strip of lead metal is placed in a solution of copper chloride, then lead chloride solution and copper metal are formed. 

CuCl₂ (aq) (green solution) +  Pb (s) → PbCl₂ (aq) (Lead Chloride) (colourless solution) + Cu (s) (red brown)

As Lead (Pb) is more reactive than Copper (Cu)

5. When a copper strip is placed in a solution of silver nitrate, then copper nitrate solution and silver metal are formed. 

2AgNO₃ (aq) (colourless solution) + Cu (s) (red brown) → Cu(NO₃)₂ (aq) (blue solution) + 2Ag (s) (Greyish white)

As Copper (Cu) is more reactive than Silver (Ag)

6. Iron metal reacts with dilute hydrochloric acid to form iron(II) chloride and hydrogen gas. 

Fe (s) + 2HCl (aq) → FeCl₂ (aq) + H₂ (g)

As Iron is more reactive than Hydrogen.

7. Magnesium metal reacts with dilute hydrochloric acid to form magnesium chloride and hydrogen gas. 

Mg (s) + 2HCl (aq) → MgCl₂ (aq) + H₂ (g)

As Magnesium is more reactive than Hydrogen.

8. Sodium metal reacts with water to form sodium hydroxide solution and hydrogen gas. 

2Na (s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g)

As Sodium is more reactive than Hydrogen. 

9. Chlorine gas reacts with potassium iodide solution to form potassium chloride and iodine. 

Cl₂ (g) + 2KI (aq) → 2KCl (aq) + I₂ (s)

Chlorine displaces iodine from potassium iodide. 

10. When copper oxide is heated with magnesium powder, then magnesium oxide and copper are formed. 

CuO (s) + Mg (s) → MgO (s) + Cu (s)

Magnesium displaces Copper from from its oxide. 

12. When iron (III) oxide is heated with Aluminium powder, then aluminium oxide and iron metal is formed. The excessive heat produced during the reaction makes the iron to be melted. 

Fe₂O₃ (s) + 2Al (s) → Al₂O₃ (s) + 2Fe (l) (molten iron)