Science test Science Class 8 0% 6 votes, 3.8 avg 8 Time Limit 15 minutes Maximum Allowed Time Is over Your Paper Successfully Sent. school1 Science Class 8 Science 1 / 50 Define biodiversity and explain its importance. Biodiversity refers to the extinction of species. It has no importance. Biodiversity refers to the number of animal species. Biodiversity refers to the variety of living organisms on Earth. It is important because it ensures the stability of ecosystems, provides resources for human survival, and has aesthetic and cultural value. 2 / 50 Describe the action and reaction forces according to Newton's third law of motion. Newton's third law of motion states that action and reaction forces have the same direction and magnitude. Newton's third law of motion states that action and reaction forces are unrelated to each other. Newton's third law of motion states that for every action, there is an equal and opposite reaction. When one object exerts a force on another, the second object exerts an equal force in the opposite direction. 3 / 50 Explain the concept of the boiling point of a substance. The temperature at which a substance changes from gas to liquid The temperature at which a substance changes from liquid to solid The temperature at which a substance changes from liquid to gas throughout the liquid 4 / 50 Describe the characteristics of Monera and give examples. Monera are prokaryotic, unicellular organisms with no nucleus. Examples include bacteria and cyanobacteria. Monera are complex, multicellular organisms with specialized organs. Examples include plants and animals. Monera are multicellular organisms with a well-defined nucleus. Examples include fungi and algae. 5 / 50 Describe the process of diffusion with an example. Diffusion is the mixing of particles of two substances due to their random motion. Example: Spreading perfume in a room. Diffusion is the movement of particles from a region of lower concentration to higher concentration. Example: Lighting a candle. Diffusion is the separation of substances through a semipermeable membrane. Example: Cooking pasta. 6 / 50 Describe the process of diffusion with an example. Diffusion is the mixing of particles of two substances due to their random motion. Example: Spreading perfume in a room. Diffusion is the separation of substances through a semipermeable membrane. Example: Cooking pasta. Diffusion is the movement of particles from a region of lower concentration to higher concentration. Example: Lighting a candle. 7 / 50 How does the modern atomic model differ from Bohr's model? The modern atomic model suggests that electrons are present inside the nucleus. The modern atomic model retains the fixed orbits of electrons as in Bohr's model. The modern atomic model describes the behavior of electrons as existing in electron clouds or orbitals, unlike Bohr's fixed orbits. 8 / 50 Explain the structure and function of the cell membrane. The cell membrane is the site of protein synthesis in the cell. The cell membrane stores genetic information. The cell membrane is a selectively permeable barrier that controls the entry and exit of substances in and out of the cell. It is composed of a lipid bilayer with embedded proteins. 9 / 50 How does sublimation differ from evaporation? Sublimation is the conversion of gas into a liquid, while evaporation is the conversion of a liquid into a gas at its surface Sublimation is the conversion of solid into a gas without passing through the liquid state, while evaporation is the conversion of a liquid into a gas at its surface Sublimation is the conversion of gas into a solid, while evaporation is the conversion of a solid into a liquid 10 / 50 Describe the Bohr's model of the atom. Bohr's model states that electrons are located outside the nucleus. Bohr's model suggests that electrons move randomly within the nucleus. Bohr's model proposes that electrons move in fixed orbits around the nucleus, and each orbit has a specific energy level. 11 / 50 Explain the characteristics of particles of matter. Attract each other Stationary particles No kinetic energy 12 / 50 Describe the concept of escape velocity and its significance. Escape velocity is the velocity at which an object can travel indefinitely in space. It has no significance. Escape velocity is the velocity at which an object enters a planet's atmosphere. Escape velocity is the minimum velocity required for an object to overcome the gravitational pull of a celestial body and enter space. It is significant for launching spacecraft and satellites into orbit. 13 / 50 Define subatomic particles - electrons, protons, and neutrons. Electrons are negatively charged particles found outside the nucleus. Protons are positively charged particles located in the nucleus. Neutrons are neutral particles also found in the nucleus. Electrons are negatively charged particles found in the nucleus. Protons are positively charged particles located outside the nucleus. Neutrons are neutral particles located outside the nucleus. Electrons are positively charged particles found outside the nucleus. Protons are negatively charged particles located in the nucleus. Neutrons are positively charged particles found outside the nucleus. 14 / 50 Define the term 'boiling point elevation.' The decrease in temperature at which a substance boils when a solute is added to it The temperature at which a liquid changes into a gas The increase in temperature at which a substance boils when a solute is added to it 15 / 50 What is photosynthesis? Explain the process. Photosynthesis is the process by which cells produce ATP. Photosynthesis is the process by which plants and some other organisms convert light energy, carbon dioxide, and water into glucose and oxygen using chlorophyll in the presence of sunlight. Photosynthesis is the breakdown of glucose to release energy. 16 / 50 What happens to the rate of evaporation when the surface area of the liquid is increased? It increases It remains the same It decreases 17 / 50 What are mitochondria, and what is their role in a cell? Mitochondria are storage organelles for water and nutrients. Mitochondria are involved in the synthesis of DNA. Mitochondria are membrane-bound organelles responsible for energy production (ATP synthesis) through cellular respiration. 18 / 50 What is the universal law of gravitation? The universal law of gravitation states that only large masses attract each other. The universal law of gravitation states that every mass attracts every other mass with a force that is inversely proportional to the product of their masses. The universal law of gravitation states that every mass attracts every other mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. 19 / 50 Define force and give its SI unit. Force is a push or pull on an object resulting from the interaction between objects. Its SI unit is the newton (N). Force is the velocity of an object. Its SI unit is meters per second (m/s). Force is the mass of an object. Its SI unit is the kilogram (kg). 20 / 50 Differentiate between distance and displacement. Distance and displacement are the same concepts. Distance is a vector quantity, and displacement is a scalar quantity. Distance is the total path length covered by an object, and it is a scalar quantity. Displacement is the shortest distance between the initial and final positions, and it is a vector quantity with magnitude and direction. 21 / 50 Explain the concept of valency in chemistry. Valency is the number of protons in the nucleus of an atom. Valency is the combining capacity of an element, representing the number of electrons it can gain, lose, or share to form a stable compound. Valency is the same for all elements in the periodic table. 22 / 50 Explain the concept of the gravitational constant (G). The gravitational constant (G) is a constant of proportionality in the universal law of gravitation. It represents the strength of the gravitational force and is approximately 6.674 × 10^(-11) Nm²/kg². The gravitational constant (G) is a variable that depends on the mass of the objects involved. The gravitational constant (G) is a constant of proportionality in the law of motion. It represents the acceleration due to gravity. 23 / 50 What is the role of meristematic tissue in plants? Meristematic tissue provides mechanical support to plants. Meristematic tissue is responsible for the growth and development of plant organs. Meristematic tissue stores nutrients in plants. 24 / 50 Explain the Rutherford model of the atom. The Rutherford model proposes that atoms consist of a single, indivisible particle. The Rutherford model states that electrons are present inside the nucleus. The Rutherford model suggests that atoms have a central nucleus containing protons and neutrons, with electrons orbiting around the nucleus. 25 / 50 State and explain Newton's second law of motion. Newton's second law of motion states that the mass of an object is directly proportional to the force applied to it. Newton's second law of motion states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass (F = ma). It describes how the velocity of an object changes when subjected to an external force. Newton's second law of motion states that the acceleration of an object is inversely proportional to the force applied to it. 26 / 50 What is the difference between positive and negative acceleration? Positive acceleration occurs when an object's velocity increases with time. Negative acceleration (deceleration) occurs when an object's velocity decreases with time. Positive acceleration occurs when an object is at rest. Negative acceleration occurs when an object moves at a constant velocity. Positive acceleration occurs when an object changes direction. Negative acceleration occurs when an object moves in a straight line. 27 / 50 What is the law of conservation of mass? The total mass of substances involved in a chemical reaction remains constant. The mass of a substance can change during a chemical reaction. The total mass of substances involved in a chemical reaction varies randomly. 28 / 50 Explain the concept of the boiling point of a substance. The temperature at which a substance changes from gas to liquid The temperature at which a substance changes from liquid to gas throughout the liquid The temperature at which a substance changes from liquid to solid 29 / 50 Discuss the Bohr's model of the atom. Bohr's model states that electrons are present inside the nucleus. Bohr's model proposes that electrons move in fixed orbits or energy levels around the nucleus, with each energy level having a specific energy. Bohr's model suggests that electrons move randomly within the nucleus. 30 / 50 Define a mixture and provide an example. A mixture is a pure substance with a fixed composition. Example: Oxygen A mixture is a compound made up of only one type of atom. Example: Hydrogen A mixture is a combination of two or more substances that are not chemically bonded. Example: Saltwater 31 / 50 Differentiate between solids, liquids, and gases based on their characteristics. Solids have fixed shape and volume, liquids take the shape of the container, gases have neither shape nor volume Solids are shapeless, liquids have fixed shape, gases have fixed volume Solids have neither shape nor volume, liquids take the shape of the container, gases have fixed shape and volume 32 / 50 What are isotopes? Provide an example. Isotopes are atoms of different elements with the same number of neutrons. Isotopes are atoms with the same mass number. Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons. Example: Carbon-12 and Carbon-14. 33 / 50 Explain Newton's first law of motion. Newton's first law of motion, also known as the law of inertia, states that an object at rest tends to stay at rest, and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an external force. Newton's first law of motion states that an object always accelerates when a force is applied to it. Newton's first law of motion states that an object in motion eventually comes to a stop on its own. 34 / 50 What is matter? Something without mass Anything with mass and volume Energy 35 / 50 How does sublimation differ from evaporation? Sublimation is the conversion of gas into a liquid, while evaporation is the conversion of a liquid into a gas at its surface Sublimation is the conversion of solid into a liquid, while evaporation is the conversion of a liquid into a solid Sublimation is the conversion of solid into a gas without passing through the liquid state, while evaporation is the conversion of a liquid into a gas at its surface 36 / 50 Why do objects weigh less on the Moon compared to Earth? Objects weigh less on the Moon because the Moon has more mass than Earth, resulting in a stronger gravitational force. Objects weigh less on the Moon because the Moon has less mass than Earth, resulting in a weaker gravitational force. Objects weigh the same on the Moon and Earth. 37 / 50 Describe the four major types of animal tissues. The four major types of animal tissues are epithelial tissue (covering and lining), connective tissue (support), muscular tissue (movement), and nervous tissue (control and coordination). The four major types of animal tissues are root tissue, stem tissue, leaf tissue, and flower tissue. The four major types of animal tissues are skin, bones, muscles, and blood. 38 / 50 Explain the types of plant tissues and their functions. Plant tissues include meristematic tissue (growth), permanent tissue (storage and support), and simple tissues (photosynthesis and transportation). Plant tissues are all the same and have no specific functions. Plant tissues include root tissue, stem tissue, and leaf tissue. 39 / 50 Differentiate between a vertebrate and an invertebrate. Vertebrates are aquatic animals, while invertebrates are terrestrial animals. Vertebrates have a backbone or vertebral column, while invertebrates do not have a backbone. Vertebrates have an exoskeleton, while invertebrates have an endoskeleton. 40 / 50 What are fungi? Mention their main features. Fungi are multicellular, non-photosynthetic organisms with a cell wall made of chitin. They obtain nutrients through absorption and play a vital role in decomposition. Fungi are plants with leaves and roots. Fungi are unicellular, photosynthetic organisms. 41 / 50 Define motion and rest. Motion is the change in position of an object with time. Rest is the state of an object when it does not change its position with time. Motion and rest are the same, and there is no difference between them. Motion is the distance traveled by an object, and rest is when an object is stationary. 42 / 50 Differentiate between a homogeneous and a heterogeneous mixture. A homogeneous mixture has non-uniform composition throughout. A heterogeneous mixture has a uniform composition. A homogeneous mixture consists of only one substance. A heterogeneous mixture consists of multiple substances. A homogeneous mixture has a uniform composition throughout. A heterogeneous mixture has non-uniform composition. 43 / 50 Define tissue. How are plant tissues different from animal tissues? Tissue is a group of dissimilar cells performing various functions. Plant tissues are the same as animal tissues. Tissue is a group of similar cells performing a specific function. Plant tissues include meristematic, permanent, and simple tissues, while animal tissues are categorized as epithelial, connective, muscular, and nervous tissues. Tissue is a single cell type found in both plants and animals. 44 / 50 Write the chemical formulae for the following compounds: water, carbon dioxide, and sodium chloride. Water: H2O, Carbon dioxide: CO2, Sodium chloride: NaCl Water: H2O2, Carbon dioxide: CO, Sodium chloride: NaCl Water: HO, Carbon dioxide: CO, Sodium chloride: NaCl2 45 / 50 Define acceleration and state its SI unit. Acceleration is the rate of change of velocity with time. Its SI unit is meters per second squared (m/s²). Acceleration is the rate of change of displacement with time. Its SI unit is meters per second (m/s). Acceleration is the rate of change of distance with time. Its SI unit is seconds per meter (s/m). 46 / 50 Describe the structure and function of the nucleus. The nucleus contains genetic material (DNA) and controls cellular activities. It is surrounded by a nuclear membrane with pores. The nucleus is the site of energy production in the cell. The nucleus is responsible for synthesizing proteins. 47 / 50 Explain the concept of uniform motion. Uniform motion is when an object changes its direction frequently. Uniform motion is when an object accelerates continuously. Uniform motion is when an object covers equal distances in equal intervals of time, and its speed remains constant. 48 / 50 What is the difference between speed and velocity? Speed is the rate of change of distance with time and is a scalar quantity. Velocity is the rate of change of displacement with time and is a vector quantity with magnitude and direction. Speed and velocity are the same concepts. Speed is a vector quantity, and velocity is a scalar quantity. 49 / 50 Explain the concept of momentum and its conservation. Momentum is the product of an object's mass and velocity. Momentum is conserved in a closed system, meaning the total momentum before an event is equal to the total momentum after the event, provided no external forces are acting on the system. Momentum is the force applied to an object. Momentum is not conserved in any situation. Momentum is the velocity of an object. Momentum is conserved only when objects are at rest. 50 / 50 Differentiate between simple and compound tissues in plants. Simple tissues have only one function, while compound tissues have multiple functions. Simple tissues consist of one type of cell, while compound tissues consist of more than one type of cell. Simple tissues are found in animals, while compound tissues are found in plants. Your score isShare the Test with your friends & family LinkedIn Facebook VKontakte 0% Restart quiz Exit you can rate the paper on 1 to 5 scale 1 is least liked and 5 is most liked Send feedback Maths Test 0% 0 votes, 0 avg 1 Time Limit 15 minutes Maximum Allowed Time Is over Your Paper Successfully Sent. school1 Maths Class 8 Maths 1 / 36 Construct an isosceles triangle with a base of 6 cm and equal angles of 70 degrees each. It is not possible to construct an isosceles triangle with a base of 6 cm and equal angles of 70 degrees each. An isosceles triangle with the given specifications can be constructed by drawing the base and using the compass to create equal angles of 70 degrees at each endpoint of the base. An isosceles triangle with the given specifications can be constructed by drawing the base, then creating two equal angles of 70 degrees at each endpoint of the base. 2 / 36 A shopkeeper offers a discount of 15% on a shirt priced at Rs. 800. Calculate the discounted price. The discounted price of the shirt is Rs. 680. The discounted price of the shirt is Rs. 760. The discounted price of the shirt is Rs. 720. 3 / 36 Expand and simplify the expression: (x - 3)(x + 3). The expanded and simplified expression is x² + 6x + 9. The expanded and simplified expression is x² - 9. The expanded and simplified expression is x² - 6x - 9. 4 / 36 Determine the number of edges in a triangular pyramid. A triangular pyramid has 12 edges. A triangular pyramid has 6 edges. A triangular pyramid has 9 edges. 5 / 36 Express 5^3 in exponential notation. 5^3 is expressed as 75. 5^3 is expressed as 125. 5^3 is expressed as 15. 6 / 36 Calculate the volume of a cylinder with a radius of 4 cm and height 10 cm. Use π (pi) as 22/7. The volume of the cylinder is 440 cubic cm. The volume of the cylinder is 880 cubic cm. The volume of the cylinder is 176 cubic cm. 7 / 36 Using a compass and ruler, construct a perpendicular bisector of a line segment AB, where AB measures 10 cm. The perpendicular bisector can be constructed by drawing an arc from points A and B, then connecting the intersections with a line segment that is perpendicular to AB and bisects it. It is not possible to construct a perpendicular bisector. The perpendicular bisector can be constructed by drawing a straight line through the midpoint of AB. 8 / 36 Determine the surface area of a sphere with a radius of 6 cm. Use π (pi) as 22/7. The surface area of the sphere is 264 square cm. The surface area of the sphere is 452 square cm. The surface area of the sphere is 792 square cm. 9 / 36 Calculate the perimeter of a rectangle with length 6 cm and width 4 cm. The perimeter of the rectangle is 20 cm. The perimeter of the rectangle is 10 cm. The perimeter of the rectangle is 24 cm. 10 / 36 Calculate the value of 4³ - 3³. The value of 4³ - 3³ is 73. The value of 4³ - 3³ is 16. The value of 4³ - 3³ is 37. 11 / 36 Factorize the expression: 6x² - 18x. The factored expression is 18x². The factored expression is 6(x - 3). The factored expression is 6x(x - 3). 12 / 36 Identify the 3D shape that has 6 faces, all of which are rectangles. The 3D shape is a triangular pyramid. The 3D shape is a rectangular prism or cuboid. The 3D shape is a cylinder. 13 / 36 If the cost of 5 pens is Rs. 30, what is the cost of 12 pens? The cost of 12 pens is Rs. 72. The cost of 12 pens is Rs. 60. The cost of 12 pens is Rs. 90. 14 / 36 Construct an angle of 60 degrees using a compass and ruler. An angle of 60 degrees can be constructed by drawing a straight line, then using the compass to create a 60-degree angle from a specific point on the line. It is not possible to construct an angle of 60 degrees. An angle of 60 degrees can be constructed by simply using a ruler to draw a straight line. 15 / 36 Determine the sum of the angles in a quadrilateral. The sum of the angles in a quadrilateral is 180 degrees. The sum of the angles in a quadrilateral is 360 degrees. The sum of the angles in a quadrilateral is 90 degrees. 16 / 36 Determine the square root of 169. The square root of 169 is 13. The square root of 169 is 15. The square root of 169 is 11. 17 / 36 Find the area of a rectangle with length 8 cm and width 5 cm. The area of the rectangle is 20 square cm. The area of the rectangle is 13 square cm. The area of the rectangle is 40 square cm. 18 / 36 Calculate the mean (average) of the following set of numbers: 10, 15, 20, 25, and 30. The mean of the numbers is 25. The mean of the numbers is 20. The mean of the numbers is 15. 19 / 36 Calculate the total number of vertices in a cube. A cube has 8 vertices. A cube has 6 vertices. A cube has 12 vertices. 20 / 36 Given the data: 12, 14, 18, 12, 16, 14, 20, 12, 16, 14, find the mode. The mode of the data is 16. The mode of the data is 12 and 14 (bimodal). The mode of the data is 20. 21 / 36 If the ratio of the ages of two friends is 5:3 and the older friend is 21 years old, how old is the younger friend? The younger friend is 18 years old. The younger friend is 15 years old. The younger friend is 12 years old. 22 / 36 Find the least number which must be subtracted from 3375 to make it a perfect cube. The least number that must be subtracted from 3375 to make it a perfect cube is 125. The least number that must be subtracted from 3375 to make it a perfect cube is 100. The least number that must be subtracted from 3375 to make it a perfect cube is 64. 23 / 36 Calculate 2^5. 2^5 is equal to 32. 2^5 is equal to 25. 2^5 is equal to 64. 24 / 36 Calculate the sum of the rational numbers 3/5 and 1/3. The sum of 3/5 and 1/3 is 8/15. The sum of 3/5 and 1/3 is 4/8. The sum of 3/5 and 1/3 is 14/15. 25 / 36 If 3x - 4 = 11, what is the value of x? The value of x is 15. The value of x is 5. The value of x is 7. 26 / 36 Simplify the expression: 3x - 2y + 5x + 3y. The simplified expression is 5xy. The simplified expression is 3x + 2y. The simplified expression is 8x + y. 27 / 36 Identify the type of quadrilateral with all sides of equal length and all angles of equal measure. The type of quadrilateral is a parallelogram. The type of quadrilateral is a square. The type of quadrilateral is a rectangle. 28 / 36 Calculate the value of √144 + √25. The value of √144 + √25 is 11. The value of √144 + √25 is 12. The value of √144 + √25 is 13. 29 / 36 Express the rational number 9/12 in its simplest form. The simplest form of 9/12 is 2/3. The simplest form of 9/12 is 3/4. The simplest form of 9/12 is 4/3. 30 / 36 Find the least number which must be added to 1056 to make it a perfect square. The least number that must be added to 1056 to make it a perfect square is 16. The least number that must be added to 1056 to make it a perfect square is 14. The least number that must be added to 1056 to make it a perfect square is 12. 31 / 36 Determine the cube root of 343. The cube root of 343 is 7. The cube root of 343 is 5. The cube root of 343 is 9. 32 / 36 Solve the equation 2x - 5 = 7 to find the value of x. The value of x is 2. The value of x is 6. The value of x is 12. 33 / 36 Solve the equation 2(x + 3) = 14 to find the value of x. The value of x is 7. The value of x is 8. The value of x is 4. 34 / 36 Calculate the median of the data set: 8, 12, 15, 18, 20, 22, 25, 30, 35. The median of the data set is 20. The median of the data set is 25. The median of the data set is 18. 35 / 36 Simplify the expression: (3^4) / (3^2). The simplified expression is 3^2. The simplified expression is 3^8. The simplified expression is 3^6. 36 / 36 Determine whether the following numbers are rational or irrational: 5/8, √25, and 0.333... 5/8 is irrational, √25 is irrational, and 0.333... is irrational. 5/8 is rational, √25 is rational, and 0.333... is rational. 5/8 is rational, √25 is irrational, and 0.333... is rational. Your score isShare the Test with your friends & family LinkedIn Facebook VKontakte 0% Restart quiz Exit you can rate the paper on 1 to 5 scale 1 is least liked and 5 is most liked Send feedback
