Model question paper solved science sslc, High school final essays of Environmental science

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M O D E L Q U E S T I O N P A P E R S

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Prepared By SANJEEVKUMAR ISARADDI PRINTABLE VERSION

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KARNATAKA SCHOOL EXAMINATION AND ASSESSMENT BOARD

Malleshwaram, Bengaluru

S.S.L.C. MODEL QUESTION PAPER

Subject :

I. Four alternatives are given for each of the following questions / incomplete statements. Choose the correct alternative and write the complete answer along with its letter of alphabet. 2 ×

1. The S I unit of potential difference is (A) volt (V) (B) ampere (A) Ans : (A) volt (V)
2. The reciprocal of focal length of lens is (A) the power of lens (C) equal to the sum of object distance and image distance (D) equal to the difference between the object distance and image distance Ans : (A) the power of lens II. Answer the following questions : 2
3. Write the symbols of the following components used in the electric circuit. (i) Dry cell (ii) Rheostat Ans : (i) Dry cell
4. Observe the below figure. When switch is closed, does the B end of the solenoid attract the N end of the bar magnet? Clarify the answer. Ans : B end of the solenoid behaves as magnet

KARNATAKA SCHOOL EXAMINATION AND ASSESSMENT BOARD

Malleshwaram, Bengaluru – 560 003

S.S.L.C. MODEL QUESTION PAPER – 1 ( 202

Subject : SCIENCE

PART – A

( PHYSICS )

I. Four alternatives are given for each of the following questions / incomplete statements. Choose the correct alternative and write the complete answer along × 1 = 2 The S I unit of potential difference is ampere (A) (C) coulomb (C) (D) ohm meter ( The reciprocal of focal length of lens is (B) the radius of curvature of lens ) equal to the sum of object distance and image distance equal to the difference between the object distance and image distance II. Answer the following questions : 2 × 1 = 2 Write the symbols of the following components used in the electric circuit. (ii) Rheostat Observe the below figure. When switch is closed, does the B end of the solenoid attract the N end of the bar magnet? Clarify the answer. B end of the solenoid behaves as North pole, hence it repels the N end of the bar

KARNATAKA SCHOOL EXAMINATION AND ASSESSMENT BOARD

I. Four alternatives are given for each of the following questions / incomplete statements. Choose the correct alternative and write the complete answer along ohm meter (Ωm) equal to the difference between the object distance and image distance Write the symbols of the following components used in the electric circuit. Observe the below figure. When switch is closed, does the B end of the solenoid the N end of the bar

1. Explain an activity of obtaining magnetic field lines around a bar magnet using a compass needle.  Take a small compass and a bar magnet. Place a magnet on a sheet of white paper fixed on a drawing board.  Place the compass near the north pole of the ends of the needle.  Now move the needle to a new position such that the south pole occupies the position previously occupied by its north pole.  In this way proceed step by step till we reach the south pole of the magnet. J the points marked on the paper by a smooth curve. This represents field line.  Repeating above procedure we can draw as many lines as possible. Explain experiment that shows ‘a current carrying conductor when kept in the magnetic field experiences a mechanical force.’  Take a small aluminium rod and suspend it horizontally using connecting wires.  Place a strong horse-shoe magnet in such a way that poles with the magnetic field directed upwards.  Connect the aluminium rod in series with a battery, a key and a rheostat.  Now pass the current through the aluminium rod in one particular direction.  The rod displaces towards one si  Reverse the direction of current flowing through the rod. The rod displaces towards the opposite side.
2. Draw a ray diagram to show the image formation when an object is kept beyond ‘C’ in front of a concave mirror. Mention the nature and position of image formed. [C: Centre of curvature of mirror] Ans : Position of the image : between C and F Nature of the image : real , inverted and Explain an activity of obtaining magnetic field lines around a bar magnet using Take a small compass and a bar magnet. Place a magnet on a sheet of white paper fixed on a drawing board. Place the compass near the north pole of the magnet mark the position of two Now move the needle to a new position such that the south pole occupies the position previously occupied by its north pole. In this way proceed step by step till we reach the south pole of the magnet. J the points marked on the paper by a smooth curve. This represents field line. Repeating above procedure we can draw as many lines as possible. OR Explain experiment that shows ‘a current carrying conductor when kept in the magnetic field experiences a mechanical force.’ Take a small aluminium rod and suspend it horizontally using connecting wires. shoe magnet in such a way that rod lies between the two poles with the magnetic field directed upwards. Connect the aluminium rod in series with a battery, a key and a rheostat. Now pass the current through the aluminium rod in one particular direction. The rod displaces towards one side. Reverse the direction of current flowing through the rod. The rod displaces towards the opposite side. Draw a ray diagram to show the image formation when an object is kept beyond ‘C’ in front of a concave mirror. Mention the nature and position of image formed. [C: Centre of curvature of mirror] between C and F inverted and smaller. Explain an activity of obtaining magnetic field lines around a bar magnet using Take a small compass and a bar magnet. Place a magnet on a sheet of white magnet mark the position of two Now move the needle to a new position such that the south pole occupies the In this way proceed step by step till we reach the south pole of the magnet. Join the points marked on the paper by a smooth curve. This represents field line. Repeating above procedure we can draw as many lines as possible. Explain experiment that shows ‘a current carrying conductor when kept in the Take a small aluminium rod and suspend it horizontally using connecting wires. rod lies between the two Connect the aluminium rod in series with a battery, a key and a rheostat. Now pass the current through the aluminium rod in one particular direction. Reverse the direction of current flowing through the rod. The rod displaces Draw a ray diagram to show the image formation when an object is kept beyond ‘C’ in front of a concave mirror. Mention the nature and position of the

V. Answer the following question : 1 × 4 = 4

1. a) Observe the below table. Which of the below listed electrical appliances consumes more energy? Electrical Appliances Electric power Time of use T.V 250W 4 hrs Toaster 1200W 1 hrs Ans  Energy consumed by TV : 250 𝑊 𝑥 4ℎ = 1000𝑊ℎ  Energy consumed by Toaster : 1200 𝑊 𝑥 1ℎ = 1200𝑊ℎ  Hence, Energy consumed by Toaster is more. b) 2 Ω and 4 Ω resistors are connected in parallel. If 6 Ω resistor is used in place of 4 Ω, then find the difference between the total resistance obtained in both of these arrangements.  Total resistance when 2 Ω and 4 Ω resistors are connected in parallel. ଵ ோುଵ

ଵ ଶΩ

ଵ ସΩ

ଶାଵ ସ

ଷ ସ So, Rp 1 = ସ ଷ  Total resistance when 2 Ω and 6 Ω resistors are connected in parallel. ଵ ோುଶ

ଵ ଶΩ

ଵ ଺Ω

ଷାଵ ଺

ସ ଺

ଶ ଷ So, Rp 2 = ଶ ଷ  The difference between the total resistance obtained in both of these arrangements. Rp 1 - Rp 2 = ସ ଷ

ଶ ଷ

ସିଶ ଷ

ଶ ଷ OR a) A 350W bread toaster is used 6 hours a day. A 250W iron box is used 4 hours a day. If these appliances are used for 30 days, then calculate the total cost of the energy consumption at the rate of Rs. 4 for 1kWh. Ans :  Energy consumed by bread toaster : 350 𝑥 6 𝑥 30 = 63000 𝑊ℎ 𝑜𝑟 63 𝑘𝑊ℎ  Energy consumed by Iron box: 250 𝑥 4 𝑥 30 = 30000 𝑊ℎ 𝑜𝑟 30 𝑘𝑊ℎ  Total Energy consumed 63 + 30 = 93 𝑘𝑊ℎ  Total cost of the energy consumed is 93 𝑥 4 = 𝑅𝑠. 372

1. Analyse the experiment expressed in the above figure. The molecular formulae of the solution ‘Y’ that gives a yellow colour another product that forms here respectively are Ans : (B) PbI 2 and KNO 3
2. A property of carbon that is responsible (A) tetravalency (B) catenation Ans : (B) catenation VII. Answer the following questions :
3. How do you detect a base using blue litmus paper? Ans : When blue litmus dipped in acid it turns to red, it retain its blue color when dipped in base
4. What are the applications of the thermite reaction? Ans : It is used for joining the railway tracks and cracked machine parts
5. Write the structural formula of an unsatu four carbon atoms and a ketone functional group. Ans : VIII. Answer the following questions : 3
6. Draw the diagram of the arrangement of apparatus used to show the reaction of zinc granules with dilute sulphuric acid and label the hydrogen gas bubbles. Ans Analyse the experiment expressed in the above figure. The molecular formulae of the solution ‘Y’ that gives a yellow colour precipitate by reacting with KI solution and the another product that forms here respectively are (A) Pb(NO 3 ) 2 and KNO 3 (B) PbI (C) Pb(NO 3 ) 2 and KI (D) Pb(NO 3 ) A property of carbon that is responsible for giving rise large molecules is catenation (C) inflammability (D) allotropism VII. Answer the following questions : 3 × 1 = 3 How do you detect a base using blue litmus paper? dipped in acid it turns to red, it retain its blue color when What are the applications of the thermite reaction? for joining the railway tracks and cracked machine parts Write the structural formula of an unsaturated carbon compound containing four carbon atoms and a ketone functional group. OR . Answer the following questions : 3 × 2 = 6 Draw the diagram of the arrangement of apparatus used to show the reaction of zinc granules with dilute sulphuric acid and label the hydrogen gas bubbles. Analyse the experiment expressed in the above figure. The molecular formulae of the solution ‘Y’ that gives a yellow precipitate by reacting with KI solution and the another product that forms here respectively are PbI 2 and KNO 3 ) 2 and K 2 SO 4 for giving rise large molecules is allotropism dipped in acid it turns to red, it retain its blue color when rated carbon compound containing Draw the diagram of the arrangement of apparatus used to show the reaction of zinc granules with dilute sulphuric acid and label the hydrogen gas bubbles.

1. a) Name the salts responsible for the hardness of water? Ans : Calcium salts like ,  Calcium bicarbonate , Calcium sulfate , Calcium chloride Magnesium salts like,  Magnesium bicarbonate , Magnesium sulfate ,Magnesium chloride – MgCl₂ b) Write the name and the molecular formula of the simplest hydrocarbon.  Name of the simplest hydrocarbon - Methane  It’s molecular formula - CH
2. Draw the diagram to the arrangement of the apparatus used in the electrolytic refining of copper and label cathode. Ans : IX. Answer the following questions : 3 × 3 = 9
3. Write the balanced chemical equations for the following word equations. (i) Manganese oxide + hydrochloric acid → manganese chloride + chlorine + water (ii) Calcium hydroxide + carbon dioxide → calcium carbonate + water (iii) Zinc carbonate → zinc oxide + Carbon dioxide i) MnO 2 + 4HCl → MnCl 2 + 2H 2 O + Cl 2 ii) Ca(OH) 2 + CO 2 → CaCO 3 + H 2 O iii) ZnCO 3 → ZnO + CO 2 OR Convert the following chemical reactions into chemical equations. (i) Ammonia forms when nitrogen gas reacts with hydrogen gas. (ii) Sodium oxide reacts with water to form sodium hydroxide. (iii) By reacting with water potassium metal produces potassium hydroxide and hydrogen gas.

a) Explain the formation of magnesium chloride molecule by the transfer of electrons.  Atomic number of magnesium in last shell is 2.  Atomic number of chlorine is 17. Electron configuration is 2, 8 , 7. Electrons in last shell are 7.  magnesium gives 2 electron to configuration.  By loosing two electron magnesium cation , while by gaining an electron chlorine gets a unit negative charge and becomes Cl

• anion.  magnesium and chloride ions, being oppositely charg are held by strong electrostatic b) How is pure zinc obtained from zinc oxide? By using reducing agents like Carbon(coke) , Zinc oxide get reduced to pure Zinc 𝑍𝑛𝑂 X. Answer the following question : 1

1. a) Write the structures of n n-butane b) What is esterification? How ethene is obtained from ethanol? Reaction between an acid and an alcohol to produce esters is called esterification. Heating ethanol with excess concentrated sulphuric acid results in the dehydration of ethanol to give ethene – 𝐶𝐻ଷ𝐶𝐻ଶ𝑂𝐻 a) Explain the formation of magnesium chloride molecule by the transfer of magnesium is 12. Electron configuration is 2, 8 , Atomic number of chlorine is 17. Electron configuration is 2, 8 , 7. Electrons in electron to two different Chlorine atoms to attain octave magnesium will become positively charged cation , while by gaining an electron chlorine gets a unit negative charge and and chloride ions, being oppositely charged, attract each other and are held by strong electrostatic forces of attraction called ionic bond. b) How is pure zinc obtained from zinc oxide? By using reducing agents like Carbon(coke) , Zinc oxide get reduced to pure Zinc 𝑍𝑛𝑂 + 𝐶 ு௘௔௧ ሱ⎯⎯⎯⎯⎯⎯ሮ 𝑍𝑛 + 𝐶𝑂 . Answer the following question : 1 × 4 = 4 a) Write the structures of n-butane and isobutane. isobutane. What is esterification? How ethene is obtained from ethanol? nd an alcohol to produce esters is called esterification. Heating ethanol with excess concentrated sulphuric acid results in the dehydration of 𝑂𝐻 ஼௢௡௖ ுమௌைర ሱ⎯⎯⎯⎯⎯⎯⎯ሮ 𝐶𝐻ଶ = 𝐶𝐻ଶ + 𝐻ଶ𝑂 a) Explain the formation of magnesium chloride molecule by the transfer of . Electron configuration is 2, 8 , 2. Electron Atomic number of chlorine is 17. Electron configuration is 2, 8 , 7. Electrons in to attain octave become positively charged Mg

a cation , while by gaining an electron chlorine gets a unit negative charge and ed, attract each other and forces of attraction called ionic bond. By using reducing agents like Carbon(coke) , Zinc oxide get reduced to pure Zinc nd an alcohol to produce esters is called esterification. Heating ethanol with excess concentrated sulphuric acid results in the dehydration of

a) Write the dot structures of nitrogen and propyne molecules. Nitrogen b) Explain the cleansing action of soap on dirt.  Soaps are sodium or potassium salts of long  Soap molecules form micelles, in which the faces outside  Carbon chain of the soap interacts with oil or dirt.  This forms emulsion in water. The soap molecules pull out the dirt and wash the clothes clean. XI. Four alternatives are given for statements. Choose the correct alternative and write with its letter of alphabet.

1. An enzyme that secretes by the pancreas to digest protein is (A) amylase (B) pepsin Ans : (C) trypsin
2. In a zygote there are 24 pairs of chromosomes. Then the number of chromosomes present in the gametes are (A) 24 pairs (B) 48 Ans : (D) 24
3. Observe the figure given below. The name of the part ‘X’ and its function is

OR

a) Write the dot structures of nitrogen and propyne molecules. Propyne b) Explain the cleansing action of soap on dirt. Soaps are sodium or potassium salts of long-chain carboxylic acids. Soap molecules form micelles, in which the ionic end interacts with water and Carbon chain of the soap interacts with oil or dirt. This forms emulsion in water. The soap molecules pull out the dirt and wash the

PART – C

( BIOLOGY )

alternatives are given for each of the following questions /incomplete statements. Choose the correct alternative and write the complete answer along 3 × 1 = 3 An enzyme that secretes by the pancreas to digest protein is pepsin (C) trypsin (D) lipase In a zygote there are 24 pairs of chromosomes. Then the number of chromosomes 48 (C) 6 pairs (D) 24 below. The name of the part ‘X’ and its function is chain carboxylic acids. ionic end interacts with water and This forms emulsion in water. The soap molecules pull out the dirt and wash the each of the following questions /incomplete the complete answer along In a zygote there are 24 pairs of chromosomes. Then the number of chromosomes below. The name of the part ‘X’ and its function is

a) In which form the excess glucose is stored in plants and animals? Ans : Stored in the form of Starch in plants, while as glycogen in animals b) Name the structures of the humans small intestine that absorb digested food. Ans : Tiny finger like projections called Villi

1. Why does the stem of a growing plant bend towards the light? Explain. Ans : When growing plants detect light, a hormone called auxin, synthesized at the shoot tip, helps the cells to grow longer.  When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot.  This concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from light.  Thus, the plant appears to bend towards light. OR Write any two differences between central nervous system and peripheral nervous system. Central Nervous System Peripheral Nervous System Consists of the brain and spinal cord. Consists of nerves that branch out from the brain and spinal cord. Controls the processing and coordination of information. Carries messages between the CNS and the rest of the body. XIV. Answer the following questions : 3 × 3 = 9
2. a) Ozone layer is a boon to the life on the earth. Justify. Ans : Because it shields Earth from dangerous UV rays and protects living organisms. These rays can cause skin cancer, cataracts in humans. b) The organisms of which trophic level in a food chain are most affected by biological magnification? Why? Ans : The organisms of hogher trophic level are more affected  Because, the concentration of harmful chemicals goes on increasing with every next trophic level in a food chain. 35 Explain: a) The determination of the height of a plant by genes.  Plant height could be depend on the amount of a particular plant hormone.  Tallness is the dominant gene that triggers the secretion of hormone and plant will be tall. The recessive gene suppress the secretion of that hormone and plant will be short.

b) The determination of the sex of the male child in humans. Ans : If an egg is fertilised by sperm carrying Y-chromosome result into male child.

1. Name the hormones that perform the following functions in humans. (i) Controlling the sugar level in the blood. (ii) Prepare the body to deal with emergency situations. (iii) Controlling the fats, proteins and carbohydrates metabolism. Ans : i) Insulin hormone ii) Adrenaline hormone iii) Thyroxin hormone XV. Answer the following questions : 1 × 4 = 4
2. Draw a diagram showing the schematic sectional view of the human heart. Label the following parts. (i) Septum (ii) Right atrium XVI. Answer the following questions : 1 × 5 = 5
3. a) List the three methods of contraception that are usually followed by human beings.  Use of condoms, cervical caps and diaphragm.  Use of oral pills.  Copper-T or loop is placed in uterus to prevent pregnancy.  Surgical method - Vasectomy in male and Tubectomy in females. b) What is the function of the vas deferens and prostate gland in the human male reproductive system?

KARNATAKA SCHOOL EXAMINATION AND ASSESSMENT BOARD

Malleshwaram, Bengaluru – 560 003

S.S.L.C. MODEL QUESTION PAPER – 2 (2025-26)

Subject : SCIENCE

PART – A

( PHYSICS )

I. Four alternatives are given for each of the following questions / incomplete statements. Choose the correct alternative and write the complete answer along with its letter of alphabet. 2 × 1 = 2

1. The S I unit of electric current is (A) ampere (A) (B) ohm (Ω ) (C) volt (V) (D) Watt (W) Ans : (A) ampere (A)
2. Observe the figure given below. The magnetic field at the centre ‘C’ of circular coil is (A) Zero (B) I (C) 2I 1 (D) 2I 2 Ans : (A) Zero II. Answer the following questions : 2 × 1 = 2
3. Which mirror is used as rear view mirror? Ans : Convex mirror
4. List any two suggestions to avoid the overload in domestic electric circuit. Ans : (i) The wires used in the circuit must be coated with good insulating materials (ii) The circuit must be divided into different sections and a safety fuse must be used in each section. (iii) High power appliances like air-conditioner, refrigerator, a water heater, etc. should not be used simultaneously. (iv) Avoid connecting too many appliances to a single socket. (any two.... )

III. Answer the following questions : 3 × 2 = 6

1. Draw a simple electric circuit. Label ammeter and voltmeter. Ans :
2. An electric motor receives 10A electric current from 220V electric source. Find the power of motor. Ans : Electric Power P = V x I = 220V x 10A = 2200W OR 2.2kW
3. Draw a diagram of experiment conducted by Newton to show the recombination of white light. Ans : IV. Answer the following questions : 3 × 3 = 9
4. a) State two laws of reflection of light. (i) The incident ray, the reflected ray and the normal, all lie on the same plane at the point of incidence. (ii) The angle of incidence is equal to the angle of reflection. b) What is magnification of mirror? What does the negative sign indicate in the magnification value? Ans : Magnification of a mirror is the ratio of the height of image to the height of object. Negative sign of the magnification value indicates that the image formed is real. OR

Ans : When we stretch the thumb, forefinger, and middle finger of our left hand mutually perpendicular to each other:  Forefinger shows the direction of magnetic field  Middle finger shows the direction of current  Thumb then gives the direction of the force or motion of the conductor. c) What is the potential difference between live wire and neutral wire in domestic electric circuit in our country? Ans : In India it is , 220V V. Answer the following question : 2 × 4 = 8

1. a) State Joule’s law of heating and name four appliances which work on the heating effect of electricity. Ans : Joule’s law of heating states that the amount of heat produced in a conductor is  directly proportional to the square of the current,  directly proportional to the resistance of the conductor,  directly proportional to the time for which current flows through it. Appliances those work on the heating effect of electricity are - Electric iron , Electric heater, Electric oven, Electric kettle, Electric toasters, geysers, hair dryers etc, b) Give reason. (i) The tungsten is used almost exclusively for filament of electric lamps. Ans : Tungsten has a very high melting point and high resistance. (ii) Copper and aluminium wires are usually employed for electricity transmission. Ans : These metals have very low electrical resistance and high conductivity, OR a) State ohm’s law. List the factors on which the resistance of conductor depends. Ans : Ohm’s law states that at a constant temperature, the electric current passing through a conductor is directly proportional to the potential difference (voltage) across its ends, The resistance of a conductor depends on - (i) length of the conductor (ii) area of cross-section (iii) temperature (iv) nature of the material.

b) “The potential difference between two points is 1V.” Mention the meaning of this statement. Ans : When 1 Joule of work is done in carrying 1Coulomb charge then potential difference is called 1 Volt.

1. a) An object is placed perpendicular to principal axis of a convex lens of focal length 20cm. If the distance of image is to be 60cm, then at what distance the object is to be placed from the lens? Ans : focal length f = 20cm , image distance v = 60cm , object distance u =? , ଵ ௩

ଵ ௨

ଵ ௙ or ଵ ௨

ଵ ௩

ଵ ௙ Then, ଵ ௨

ଵ ଺଴

ଵ ଶ଴ ଵ ௨

ଵ ଺଴

ଵ ଶ଴

ଵି ଷ ଺଴ ଵ ௨

ି ଶ ଺଴ or u = - 30cm Hence, an object should be kept at a distance of -30 cm b) The object distance and image distance of a lens are -30cm and -10 cm respectively. Decide the type of lens and nature of image. Ans : Type of the lens is concave Nature of the image is , virtual, erect and smaller than the object

PART – B

( CHEMISTRY )

VI. Four alternatives are given for each of the following questions / incomplete statements. Choose the correct alternative and write the complete answer along with its letter of alphabet. 3 × 1 = 3

1. The functional group present in pentanal is (A) - OH (B) - CHO (C) - COOH (D) - CO - Ans : (B) - CHO
2. Silver chloride turns grey when exposed to sunlight. This is because silver chloride (A) decomposes to form silver. (B) decomposes to form chlorine. (C) combines with oxygen. (D) reacts with atmospheric moisture. Ans : (A) decomposes to form silver.