Q.1 Camphor disapperars without leaving any residue. Explain?
Q.2 Why do we feel cool when we touch a piece of ice?
Ans. We feel cool because the temperature of ice is 0 deg C and our body’s temp is higher than 0 deg C.
Q.3 Convert the following:- (a) 573 K (b) 36 deg C (c) 373 deg C
Ans. 573-273 = 300 deg C
b) 36 deg C = 273+36 = 309 K
c) 373 deg C = 373+273= 646 K
b) 36 deg C = 273+36 = 309 K
c) 373 deg C = 373+273= 646 K
Q.4 Both the process of evaporation and boiling involves the change of state from liquid to gas but still they are different from each other. Justify.
Ans. Evaporation is different from boiling as evaporation is a natural phenomenon, occurs on the surface of the water and also it is a slow process whereas boiling is an artificial phenomenon , it occurs in the bulk of the liquid and is a fast process.
Q.5 Why is Kelvin considered as the best scale for measuring the temperature?
Ans. Kelvin is the best scale for measuring the temperature because it has no max temp. and it canmeasure temperature to any extent.
Q.6 How can you show that evaporation causes cooling?
Ans. When we put some acetone on our hand , after sometime we will feel coolness on our hand because the action absorbs kinetic energy from our hand & evaporates and evaporation causes cooling.
Ans. When we put some acetone on our hand , after sometime we will feel coolness on our hand because the action absorbs kinetic energy from our hand & evaporates and evaporation causes cooling.
Q.7 What is the significance of boiling point & melting point of a substance?
Ans. The significance of boiling point and melting point is that it shows the purity of the substance.
Ans. The solution turns blue because of diffusion. On heating the solution nothing will happen
Q.9 How can you justify that table is a solid?
Ans. When we apply force on the table it doesn’t change its shape because its inter molecules are tightly packed , this shows that table is solid.
Q.10 Arrange the following in decreasing order of force of attraction: Water, Salt, Oxygen,
Also, state the reason.
Ans. Salt, Water, Oxygen
Salt has the maximum force of attraction as it is a solid, followed by water as it is a liquid. Oxygen is a gas so its force of attraction is the least.
Q. 11 State characteristics of matter demonstrated by : (a) diffusion (b) Brownian motion
Ans. (a) Diffusion involves movement of different particles so that they become intermixed
uniformly .
b) Brownian motion: It is the zig-zag movement of the small particles suspended in a liquid or a gas .
Q.12 When an incense stick (agarbatti) is lighted in one corner of a room, its fragrance spreads in the
whole room quickly. Which characteristic of the particles of matter is illustrated by this observation?
Ans. Particles of matter are constantly moving.
Q.13 The boiling point of alcohol is 78 deg C. What is this temperature on Kelvin scale?
Ans. K= Deg C + 273 = 78 + 273 = 351 K
Q. 14 The Kelvin scale temperature is 0 K. What is the corresponding Celsius scale temperature?
Ans. – 273 deg C
Q. 15 What is Latent Heat of Fusion?
Ans. The latent heat of fusion (or melting) of a solid is the quanity of heat in joules required to convert 1 kilogram of the solid (at its melting point ) to liquid, without any change in temperature.
Q. 16 Define latent heat of Vaporization?
Ans. The latent heat of vaporisation of a liquid is the quantity of heat in joules required to convert 1 kilogram of the liquid (at its boiling point ) to vapour or gas, without any change in temperature.MATER IN OUR SURONDING DEFINATIONS
Matter:
matter is commonly defined as the substance of which physical objects are composed, not counting the contribution of various energy or force-fields, which are not usually considered to be matter per se (though they may contribute to the mass of objects). Matter constitutes much of the observable universe, although again, light is not ordinarily considered matter. Unfortunately, for scientific purposes, "matter" is somewhat loosely defined. It can also be defined as a physical substance that has mass and volume.
Volume:
The volume of a solid object is the three-dimensional concept of how much space it occupies, often quantified numerically. One-dimensional figures (such as lines) and two-dimensional shapes (such as squares) are assigned zero volume in the three-dimensional space.
Mass:
Mass is a fundamental concept in physics, roughly corresponding to the intuitive idea of "how much matter there is in an object". Mass is a central concept of classical mechanics and related subjects, and there are several definitions of mass within the framework of relativistickinematics (see mass in special relativity and mass in General Relativity). In the theory ofrelativity, the quantity invariant mass, which in concept is close to the classical idea of mass, does not vary between single observers in different reference frames
Diffusion:
In the second sense of diffusion is the spontaneous net movement of particles from an area of high concentration to an area of low concentration through a semi-permeable membrane. For example, diffusing molecules will move randomly between areas of high and low concentration but because there are more molecules in the high concentration region, more molecules will leave the high concentration region than the low concentration one. Therefore, there will be a net movement of molecules from high to low concentration. Initially, a concentration gradient leaves a smooth decrease in concentration from high to low which will form between the two regions. As time progresses, the gradient will grow increasingly shallow until the concentrations are equalized.
Force:
force is what causes a mass to accelerate. It may be experienced as a lift, a push, or a pull. The acceleration of the body is proportional to the vector sum of all forces acting on it (known as net force or resultant force). In an extended body, force may also cause rotation, deformation, or an increase in pressure for the body. Rotational effects are determined by the torques, while deformation and pressure are determined by the stresses that the forces create.
Pressure:
Pressure is the force per unit area applied on a surface in a direction perpendicular to that surface.
Density:
density is mass (m) per unit volume (V) — the ratio of the amount of matter in an object compared to its volume. A small, heavy object, such as a rock or a lump of lead, is denser than a larger object of the same mass, such as a piece of cork or foam.
Kinetic energy: The kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. Negative work of the same magnitude would be required to return the body to a state of rest from that velocity.
Speed:
speed is a quantity that measures the ratio of an evolution to time. Example: speed of sedimentation, speed of economic growth, speed of chemical reaction etc.
Melting point:
The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Although the phrase would suggest a specific temperature and is commonly and incorrectly used as such in most textbooks and literature, most crystalline compounds actually melt over a range of a few degrees or less. At the melting point the solid and liquid phase exist in equilibrium. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point.
Atmospheric pressure:
Atmospheric pressure is the pressure at any point in the Earth's atmosphere. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmosphericmass above their location. Similarly, as elevation increases there is less overlying atmospheric mass, so that pressure decreases with increasing elevation. A column of air 1 square inch in cross section, measured from sea level to the top of the atmosphere, would weigh approximately 14.7 lbf. A 1 m² (11 sq ft) column of air would weigh about 100 kilonewtons (equivalent to a mass of 10.2 tonnes at the surface).
Latent heat:
Latent heat:
Latent heat is the amount of energy in the form of heat released or absorbed by a substance during a change of phase (i.e. solid, liquid, or gas), - also called a phase transition.
Vaporisation:
Vaporisation:
Evaporation is the process by which molecules in a liquid state (e.g. water) spontaneously become gaseous (e.g. water vapor). It is the opposite of condensation. Generally, evaporation can be seen by the gradual disappearance of a liquid, when exposed to a significant volume of gas.
elect Categories
Fundamental Unit Of Life
1. What is plasma membrane? What are their functions?
Ans:
Ans:
- Plasma membrane also called as cell membrane, is the outer covering of a cell that separates the cell contents (protoplasm) from the surrounding medium.
- It is made up of proteins and lipids.
- It gives form (shape and size) to the cell
- It maintains the individuality of the cell (i.e. seperates cells)
- It keeps the cell contents in place
2. What are cell organelles ?
Ans: The certain specific living parts of a cell with a definite function are celled Cell organelles. All cell are found to have same organelles and together these constitute to the basic unit of life.
3. What is cellulose and its functions?
Ans: Cellulose is the main component of a plant cell wall. It is responsible for giving structural shape to the cell and also to protect the protoplasm.
4. What is a Prokaryotic cell? Give an Example.
Ans: The cells that do not have a nuclear membrane and membrane bound cell organelles (i.e. well-defined nucleus) are known as Prokaryotic Cells. Example:- Blue green algae, Bacteria, Mycoplasma etc.
5. What are the advantages of multicellularity ?
Ans:
- The division of labour in a multicellular organism increases the efficiency of the organism.
- It increases the Chance of survival.
6. What are vacuoles? What are their functions?
Ans:
- Vacuoles are clear fluid/gas filled spaces in the cytoplasm.
- In plant cells, it is larger and less in number as compared to the animal cells.
- Vacuoles help in the storage of water, food and other waste substances.
7. What is ER ? Name two types of ER. Write its main functions.
Ans:
- Endoplasmic Reticulum or ER, is a network of tube like structures found in the cytoplasm.
- The two types of ER are Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER).
- It provides channel for quick transport of materials
- It provides materials (i.e. lipids and proteins) for membrane biogenesis.
8. Write the Function of Chromatin material.
Ans: The Chromatin material mainly consists of DNA’s, therefore plays an important role in storing and transmitting hereditary information (DNA) from one generation to another.
9. Name a cell that lacks membrane. Where is it prepared?
Ans: Ribosomes is a cell organelle which lacks membrane and is prepared in the Nucleolus.
10. What is plasmolysis? What happens to a plasmolysed cell when it is placed in water ?
Ans:
- The detachment of cell membrane of the plant cell from the cell wall when put in Hypertonic Solution is known as Plasmolysis.
- The cell that has undergone plasmolysis i.e. plasmolysed cell when placed in water, the water moves into the cell from the solution due to the higher concentration of water in the solution (Endosmosis) and therefore the cell swells.
11. What do yo mean by nucleoid?
Ans: The undefined nuclear region of prokaryotic cells like blue green algae are known as nucleoid. The nucleoid contains nucleic acid but does not have any membrane covering it.
12. What are the factors which restrict the size of the cell?
Ans: The factors which restrict the size of the cell are:
- Functions of cell.
- Cell’s requirement of oxygen and other materials from the environment.
- Regulating ability of the nucleus of the cell.
13. Name the two nucleic acids present in the cell and their functions.
Ans:
- Ribose Nucleic Acid (RNA) – It helps in protein synthesis.
- Deoxyribo Nucleic Acid (DNA) – It stores heriditary information.
14. Give any two functions of plastids.
Ans:
- Chloroplast is the site of photosynthesis and helps in preparing food (in case of plant cells).
- Leucoplast are the site of storage of food.
- Chromoplast provide colour to various flowers and fruits.
15. Write down the main functions of cell wall.
Ans:
- Cell wall provides shape as well as rigidity to the cell.
- It protects the protoplasm.
- It is involved in the movement of materials in and out of the cell.
- It prevents the cell from bursting even in very dilute solution.
16. Describe in short the chief components of a nucleus.
Ans:
- Nucleoplasm – the semi-fluid part of protoplasm lying inside the nucleus, in which nucleoli and Chromatinfibers are found.
- Nucleolus – a dense, spherical, darkly stained structure, which the site of formation and store house of RNA’s.
- Nuclear Membrane- The membrane that bounds the nucleus, which semi-permeable, double layered and porous.
17. What role does a nucleus play in cellular reproduction?
Ans: The nucleus plays the central role in the cell division/reproduction. Nucleus carry the hereditary information and it divides to form two new cell by the process of cellular reproduction. Apart from that, nucleus also plays a vital role in determining when the cell will divide.
18. Write functions of lysosomes?
Ans:
- They take part in intracellular digestion of foreign particles.
- They provide energy during starvation.
- They help in defence against bacterial and viral infections.
- They remove cellular debris.
19. Define Osmosis. In what ways it is different from diffusion?
Ans:
Diffusion
Diffusion is defined as the movement of particles from a region of high concentration to a region of low concentration.
Osmosis
Osmosis is defined as the passage of water from a region of high water concentration to a region of low concentration through a Semi-permeable membrane.
Diffusion is defined as the movement of particles from a region of high concentration to a region of low concentration.
Osmosis is defined as the passage of water from a region of high water concentration to a region of low concentration through a Semi-permeable membrane.
20. Write one function each of – Ribosomes, Vacuole, Plasma Membrane
Ans:
- Ribosomes : It helps in Protein Synthesis
- Vacuole : They help in the storage of water, food and other waste substances.
- Plasma Membrane : It regulates the flow materials in and out of the cell.
1. What is plasma membrane? What are their functions?
Ans:
Ans:
- Plasma membrane also called as cell membrane, is the outer covering of a cell that separates the cell contents (protoplasm) from the surrounding medium.
- It is made up of proteins and lipids.
- It gives form (shape and size) to the cell
- It maintains the individuality of the cell (i.e. seperates cells)
- It keeps the cell contents in place
2. What are cell organelles ?
Ans: The certain specific living parts of a cell with a definite function are celled Cell organelles. All cell are found to have same organelles and together these constitute to the basic unit of life.
3. What is cellulose and its functions?
Ans: Cellulose is the main component of a plant cell wall. It is responsible for giving structural shape to the cell and also to protect the protoplasm.
4. What is a Prokaryotic cell? Give an Example.
Ans: The cells that do not have a nuclear membrane and membrane bound cell organelles (i.e. well-defined nucleus) are known as Prokaryotic Cells. Example:- Blue green algae, Bacteria, Mycoplasma etc.
5. What are the advantages of multicellularity ?
Ans:
- The division of labour in a multicellular organism increases the efficiency of the organism.
- It increases the Chance of survival.
6. What are vacuoles? What are their functions?
Ans:
- Vacuoles are clear fluid/gas filled spaces in the cytoplasm.
- In plant cells, it is larger and less in number as compared to the animal cells.
- Vacuoles help in the storage of water, food and other waste substances.
7. What is ER ? Name two types of ER. Write its main functions.
Ans:
- Endoplasmic Reticulum or ER, is a network of tube like structures found in the cytoplasm.
- The two types of ER are Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER).
- It provides channel for quick transport of materials
- It provides materials (i.e. lipids and proteins) for membrane biogenesis.
8. Write the Function of Chromatin material.
Ans: The Chromatin material mainly consists of DNA’s, therefore plays an important role in storing and transmitting hereditary information (DNA) from one generation to another.
9. Name a cell that lacks membrane. Where is it prepared?
Ans: Ribosomes is a cell organelle which lacks membrane and is prepared in the Nucleolus.
10. What is plasmolysis? What happens to a plasmolysed cell when it is placed in water ?
Ans:
- The detachment of cell membrane of the plant cell from the cell wall when put in Hypertonic Solution is known as Plasmolysis.
- The cell that has undergone plasmolysis i.e. plasmolysed cell when placed in water, the water moves into the cell from the solution due to the higher concentration of water in the solution (Endosmosis) and therefore the cell swells.
11. What do yo mean by nucleoid?
Ans: The undefined nuclear region of prokaryotic cells like blue green algae are known as nucleoid. The nucleoid contains nucleic acid but does not have any membrane covering it.
12. What are the factors which restrict the size of the cell?
Ans: The factors which restrict the size of the cell are:
- Functions of cell.
- Cell’s requirement of oxygen and other materials from the environment.
- Regulating ability of the nucleus of the cell.
13. Name the two nucleic acids present in the cell and their functions.
Ans:
- Ribose Nucleic Acid (RNA) – It helps in protein synthesis.
- Deoxyribo Nucleic Acid (DNA) – It stores heriditary information.
14. Give any two functions of plastids.
Ans:
- Chloroplast is the site of photosynthesis and helps in preparing food (in case of plant cells).
- Leucoplast are the site of storage of food.
- Chromoplast provide colour to various flowers and fruits.
15. Write down the main functions of cell wall.
Ans:
- Cell wall provides shape as well as rigidity to the cell.
- It protects the protoplasm.
- It is involved in the movement of materials in and out of the cell.
- It prevents the cell from bursting even in very dilute solution.
16. Describe in short the chief components of a nucleus.
Ans:
- Nucleoplasm – the semi-fluid part of protoplasm lying inside the nucleus, in which nucleoli and Chromatinfibers are found.
- Nucleolus – a dense, spherical, darkly stained structure, which the site of formation and store house of RNA’s.
- Nuclear Membrane- The membrane that bounds the nucleus, which semi-permeable, double layered and porous.
17. What role does a nucleus play in cellular reproduction?
Ans: The nucleus plays the central role in the cell division/reproduction. Nucleus carry the hereditary information and it divides to form two new cell by the process of cellular reproduction. Apart from that, nucleus also plays a vital role in determining when the cell will divide.
18. Write functions of lysosomes?
Ans:
- They take part in intracellular digestion of foreign particles.
- They provide energy during starvation.
- They help in defence against bacterial and viral infections.
- They remove cellular debris.
19. Define Osmosis. In what ways it is different from diffusion?
Ans:
DiffusionDiffusion is defined as the movement of particles from a region of high concentration to a region of low concentration.
Osmosis
Osmosis is defined as the passage of water from a region of high water concentration to a region of low concentration through a Semi-permeable membrane.
Osmosis is defined as the passage of water from a region of high water concentration to a region of low concentration through a Semi-permeable membrane.
20. Write one function each of – Ribosomes, Vacuole, Plasma Membrane
Ans:
- Ribosomes : It helps in Protein Synthesis
- Vacuole : They help in the storage of water, food and other waste substances.
- Plasma Membrane : It regulates the flow materials in and out of the cell.
Chapter – Motion and Rest
Distance : The distance covered by a moving object is the actual length of the path followed by the object.
Distance is a scalar quantity. SI unit of distance is Metre .
Displacement is the shortest distance covered by a moving object from the point of reference (initial
position of the body), in a specified direction.
Note: But the displacement when the bus moves from A B and then from B A is zero. SI unit of
displacement is metre. Displacement is a vector, i.e., the displacement is given by a number with proper
units and direction.
☼
When a body covers equal distances in equal intervals of time then the body is said to describe uniform
motion.
☼
When a body moves unequal distances in equal intervals of time or vice-versa, then the body is said to
describe non-uniform motion.
☼
Speed can be defined as the distance covered by a moving object in unit time
Speed = distance / time = s/t where S is the distance covered and t is the time taken. SI unit of speed is
m/s or m s-1
. Speed is a scalar quantity.
Uniform Speed : An object is said to be moving with uniform speed if it covers equal distances in equal
intervals of time.
Non-uniform : An object is said to be moving with variable speed or non-uniform speed if it covers equal
distances in unequal intervals of time or vice-versa.
Average speed : When we travel in a vehicle the speed of the vehicle changes from time to time depending upon the conditions existing on the road. In such a situation, the speed is calculated by taking the ratio of the total distance travelled by the vehicle to the total time taken for the journey. This is called the average speed.
Instantaneous speed : When we say that the car travels at an average speed of 60 km/h it does not mean that the car would be moving with the speed of 60 km/h throughout the journey. The actual speed of the car may be less than or greater than the average speed at a particular instant of time. The speed of a moving body at any particular instant of time, is called instantaneous speed.
Velocity is defined as the distance travelled in a specified direction in unit time. The distance travelled in a specified direction is displacement. Therefore, velocity can be defined as the rate of change of displacement . Velocity is defined as the distance covered by a moving object in a particular direction in unit time or speed in a particular direction. ☼ SI unit of velocity is m/s (metre/second). [ SI unit of distance is metre and that of time is second] ☼ Velocity is a vector quantity.
Acceleration : When the train starts from rest its speed increases from zero and we say that the train is accelerating. After sometime the speed becomes uniform and we say that it is moving with uniform speed that means the train is not accelerating. But as the train is nearing Mysore it slows down, which means the train is accelerating in negative direction. Again the train stops accelerating when it comes to a halt at Mysore . Acceleration is defined as the rate of change of velocity of a moving body with time
☼ Acceleration = Rate of change of velocity with time ☼ The SI unit of velocity is m/s and time is s ☼ Acceleration is a vector quantity
Positive Acceleration If the velocity of an object increases then the object is said to be moving with positive acceleration. Example: A ball rolling down on an inclined plane.
Negative Acceleration : If the velocity of an object decreases then the object is said to be moving with negative acceleration. Negative acceleration is also known as retardation or deceleration. Example: (1) A ball moving up an inclined plane. 2) A ball thrown vertically upwards is moving with a negative acceleration as the velocity decreases with time Zero Acceleration : If the change in velocity is zero, i.e., either the object is at rest or moving with uniform velocity, then the object is said to have zero acceleration. Example: a parked car, a train moving with a constant speed of 90 km/hr Uniform Acceleration : If the change in velocity in equal intervals of time is always the same, then the object is said to be moving with uniform acceleration. Example: a body falling from a height towards the
Non-uniform or Variable Acceleration : If the change in velocity in equal intervals of time is not the same, then the object is said to be moving with variable acceleration.
Uniform velocity : A body is said to be moving with uniform velocity if it covers equal distances in equal intervals of time in a specified direction.
Variable velocity A body is said to be moving with variable velocity if it covers unequal distances in equal intervals of time and vice-versa in a specified direction or if it changes the direction of motion. Circular motion : Motion along circular track is called circular motion . An object moving along a circular track with uniform speed is an example for a non - uniform motion because the direction of motion of the object goes on changing at every instant of time. Example - A car negotiating a curve with uniform speed A circle can be considered as a polygon with infinite sides and hence motion along a circular path is classified as non-uniform motion. Derivation of the First Equation of Motion Consider a particle moving along a straight line with uniform acceleration 'a'. At t = 0, let the particle be at
Average speed : When we travel in a vehicle the speed of the vehicle changes from time to time depending upon the conditions existing on the road. In such a situation, the speed is calculated by taking the ratio of the total distance travelled by the vehicle to the total time taken for the journey. This is called the average speed.
Instantaneous speed : When we say that the car travels at an average speed of 60 km/h it does not mean that the car would be moving with the speed of 60 km/h throughout the journey. The actual speed of the car may be less than or greater than the average speed at a particular instant of time. The speed of a moving body at any particular instant of time, is called instantaneous speed.
Velocity is defined as the distance travelled in a specified direction in unit time. The distance travelled in a specified direction is displacement. Therefore, velocity can be defined as the rate of change of displacement . Velocity is defined as the distance covered by a moving object in a particular direction in unit time or speed in a particular direction. ☼ SI unit of velocity is m/s (metre/second). [ SI unit of distance is metre and that of time is second] ☼ Velocity is a vector quantity.
Acceleration : When the train starts from rest its speed increases from zero and we say that the train is accelerating. After sometime the speed becomes uniform and we say that it is moving with uniform speed that means the train is not accelerating. But as the train is nearing Mysore it slows down, which means the train is accelerating in negative direction. Again the train stops accelerating when it comes to a halt at Mysore . Acceleration is defined as the rate of change of velocity of a moving body with time
☼ Acceleration = Rate of change of velocity with time ☼ The SI unit of velocity is m/s and time is s ☼ Acceleration is a vector quantity
Positive Acceleration If the velocity of an object increases then the object is said to be moving with positive acceleration. Example: A ball rolling down on an inclined plane.
Negative Acceleration : If the velocity of an object decreases then the object is said to be moving with negative acceleration. Negative acceleration is also known as retardation or deceleration. Example: (1) A ball moving up an inclined plane. 2) A ball thrown vertically upwards is moving with a negative acceleration as the velocity decreases with time Zero Acceleration : If the change in velocity is zero, i.e., either the object is at rest or moving with uniform velocity, then the object is said to have zero acceleration. Example: a parked car, a train moving with a constant speed of 90 km/hr Uniform Acceleration : If the change in velocity in equal intervals of time is always the same, then the object is said to be moving with uniform acceleration. Example: a body falling from a height towards the
Non-uniform or Variable Acceleration : If the change in velocity in equal intervals of time is not the same, then the object is said to be moving with variable acceleration.
Uniform velocity : A body is said to be moving with uniform velocity if it covers equal distances in equal intervals of time in a specified direction.
Variable velocity A body is said to be moving with variable velocity if it covers unequal distances in equal intervals of time and vice-versa in a specified direction or if it changes the direction of motion. Circular motion : Motion along circular track is called circular motion . An object moving along a circular track with uniform speed is an example for a non - uniform motion because the direction of motion of the object goes on changing at every instant of time. Example - A car negotiating a curve with uniform speed A circle can be considered as a polygon with infinite sides and hence motion along a circular path is classified as non-uniform motion. Derivation of the First Equation of Motion Consider a particle moving along a straight line with uniform acceleration 'a'. At t = 0, let the particle be at
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