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All questions of Upthrust In Fluids, Archimedes' Principle And Floatation for Class 9 Exam
How does temperature affect the density of most substances?- a) No effect on density
- b) Decreases density when heated
- c) Makes density uniform
- d) Increases density when heated
Correct answer is option 'B'. Can you explain this answer?
How does temperature affect the density of most substances?
a)
No effect on density
b)
Decreases density when heated
c)
Makes density uniform
d)
Increases density when heated
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Arien Instructors answered |
Temperature generally affects the density of most substances by decreasing their density when heated. As substances expand upon heating, their mass remains constant while their volume increases, leading to a lower density. This principle is important in various scientific and engineering applications, including thermodynamics and fluid mechanics.
Which fluid property allows a person to float more easily in the Dead Sea compared to a regular lake?- a) Temperature
- b) Viscosity
- c) Surface tension
- d) Density
Correct answer is option 'D'. Can you explain this answer?
Which fluid property allows a person to float more easily in the Dead Sea compared to a regular lake?
a)
Temperature
b)
Viscosity
c)
Surface tension
d)
Density
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Arien Instructors answered |
The property that allows a person to float more easily in the Dead Sea compared to a regular lake is the density of the fluid. The Dead Sea has a much higher salt concentration, increasing its density. This greater buoyancy makes it easier for individuals to float, as the buoyant force exceeds their weight more significantly than in less dense water.
Which of the following statements is true when an object is floating in equilibrium?- a) Buoyant force acts downward
- b) Buoyant force is less than the weight of the object
- c) Buoyant force equals the weight of the object
- d) Buoyant force is greater than the weight of the object
Correct answer is option 'C'. Can you explain this answer?
Which of the following statements is true when an object is floating in equilibrium?
a)
Buoyant force acts downward
b)
Buoyant force is less than the weight of the object
c)
Buoyant force equals the weight of the object
d)
Buoyant force is greater than the weight of the object
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Arien Instructors answered |
When an object is floating in equilibrium, the buoyant force acting on it equals the weight of the object. This balance of forces allows the object to float without rising or sinking. This principle is a key aspect of Archimedes' principle and is fundamental in fluid dynamics.
In which scenario would an object sink in water?- a) When its weight is greater than the buoyant force
- b) When its weight is less than the buoyant force
- c) When it is fully submerged
- d) When its weight is equal to the buoyant force
Correct answer is option 'A'. Can you explain this answer?
In which scenario would an object sink in water?
a)
When its weight is greater than the buoyant force
b)
When its weight is less than the buoyant force
c)
When it is fully submerged
d)
When its weight is equal to the buoyant force
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Arien Instructors answered |
An object will sink in water when its weight is greater than the buoyant force acting on it. This situation occurs because the upward force of buoyancy cannot counteract the downward gravitational force, resulting in the object sinking. This principle can be observed with denser materials that displace less water relative to their weight.
When a cork floats in water with two-thirds of its volume submerged, what does this indicate about the buoyant force and the weight of the cork?- a) Buoyant force equals the weight of the cork
- b) The cork is in a state of free fall
- c) Buoyant force is greater than the weight of the cork
- d) Buoyant force is less than the weight of the cork
Correct answer is option 'A'. Can you explain this answer?
When a cork floats in water with two-thirds of its volume submerged, what does this indicate about the buoyant force and the weight of the cork?
a)
Buoyant force equals the weight of the cork
b)
The cork is in a state of free fall
c)
Buoyant force is greater than the weight of the cork
d)
Buoyant force is less than the weight of the cork
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Arien Instructors answered |
When a cork floats with two-thirds of its volume submerged, it indicates that the buoyant force equals the weight of the cork. This balance allows the cork to float in equilibrium, demonstrating the principle of floatation where the weight of the fluid displaced by the submerged part of the cork is equal to the weight of the cork itself.
What causes the net upward force (upthrust) on a submerged object?- a) Pressure difference between the top and bottom surfaces
- b) Weight of the object
- c) Surface tension of the fluid
- d) The shape of the object
Correct answer is option 'A'. Can you explain this answer?
What causes the net upward force (upthrust) on a submerged object?
a)
Pressure difference between the top and bottom surfaces
b)
Weight of the object
c)
Surface tension of the fluid
d)
The shape of the object
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Arien Instructors answered |
The net upward force (upthrust) on a submerged object is caused by the pressure difference between the top and bottom surfaces of the object. The pressure at the deeper surface of the object is greater than that at the shallower surface, resulting in a net upward force that acts to lift the object.
What is the relationship between the volume of a submerged part of an object and the density of the fluid in which it is floating?- a) Inversely proportional
- b) No relationship
- c) Equal to its weight
- d) Directly proportional
Correct answer is option 'A'. Can you explain this answer?
What is the relationship between the volume of a submerged part of an object and the density of the fluid in which it is floating?
a)
Inversely proportional
b)
No relationship
c)
Equal to its weight
d)
Directly proportional
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Arien Instructors answered |
The relationship between the volume of the submerged part of an object and the density of the fluid in which it is floating is directly proportional. The more dense the fluid, the smaller the volume of fluid that needs to be displaced to support the object's weight, which is crucial in understanding floatation principles.
What determines the amount of buoyant force acting on an object submerged in a fluid?- a) The fluid's viscosity
- b) The volume of fluid displaced
- c) The temperature of the fluid
- d) The object's mass
Correct answer is option 'B'. Can you explain this answer?
What determines the amount of buoyant force acting on an object submerged in a fluid?
a)
The fluid's viscosity
b)
The volume of fluid displaced
c)
The temperature of the fluid
d)
The object's mass
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Arien Instructors answered |
The amount of buoyant force acting on an object submerged in a fluid is determined by the volume of fluid displaced by the object. According to Archimedes' principle, the buoyant force is equal to the weight of the fluid displaced, which depends directly on the submerged volume of the object.
What is the relationship between the density of an object and its ability to float in a fluid?- a) Only the shape of the object determines floatation
- b) The greater the density, the easier it floats
- c) The lesser the density, the easier it floats
- d) Density has no effect on floatation
Correct answer is option 'C'. Can you explain this answer?
What is the relationship between the density of an object and its ability to float in a fluid?
a)
Only the shape of the object determines floatation
b)
The greater the density, the easier it floats
c)
The lesser the density, the easier it floats
d)
Density has no effect on floatation
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Arien Instructors answered |
The relationship between density and floatation is such that the lesser the density of an object compared to the fluid, the easier it floats. If an object's density is less than that of the fluid, it will displace enough fluid to generate a buoyant force that can support its weight, allowing it to float.
Which of the following conditions must be met for an object to float?- a) The weight must be greater than the buoyant force
- b) The weight must be equal to the buoyant force
- c) The object must be fully submerged
- d) The weight must be less than the buoyant force
Correct answer is option 'B'. Can you explain this answer?
Which of the following conditions must be met for an object to float?
a)
The weight must be greater than the buoyant force
b)
The weight must be equal to the buoyant force
c)
The object must be fully submerged
d)
The weight must be less than the buoyant force
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Arien Instructors answered |
For an object to float, the weight of the object must be equal to the buoyant force acting on it. This balance allows the object to maintain its position in the fluid without sinking or rising, adhering to the principle of floatation.
If a solid object has a density greater than that of water, what will happen to it when placed in water?- a) It will remain suspended
- b) It will float
- c) It will sink
- d) It will dissolve
Correct answer is option 'C'. Can you explain this answer?
If a solid object has a density greater than that of water, what will happen to it when placed in water?
a)
It will remain suspended
b)
It will float
c)
It will sink
d)
It will dissolve
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Arien Instructors answered |
A solid object with a density greater than that of water will sink when placed in water. This is because the weight of the object exceeds the buoyant force provided by the displaced water, leading to a net downward force. This principle is commonly observed with metals and other dense materials.
What happens to the apparent weight of an object when it is submerged in a fluid?- a) It increases
- b) It remains the same
- c) It decreases
- d) It becomes negative
Correct answer is option 'C'. Can you explain this answer?
What happens to the apparent weight of an object when it is submerged in a fluid?
a)
It increases
b)
It remains the same
c)
It decreases
d)
It becomes negative
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Arien Instructors answered |
The apparent weight of an object decreases when it is submerged in a fluid due to the upthrust acting on it. The buoyant force reduces the effective weight of the object, making it feel lighter in water than in air. This concept is crucial for understanding why objects can be more easily lifted in water.
Which property of a fluid affects the upthrust experienced by an object submerged in it?- a) Surface tension
- b) Temperature
- c) Viscosity
- d) Density
Correct answer is option 'D'. Can you explain this answer?
Which property of a fluid affects the upthrust experienced by an object submerged in it?
a)
Surface tension
b)
Temperature
c)
Viscosity
d)
Density
|
|
Arien Instructors answered |
The upthrust experienced by an object submerged in a fluid is affected by the fluid's density. A denser fluid exerts a greater buoyant force on the object, increasing the upthrust. This principle is essential in applications such as designing submarines and understanding how various objects behave in different fluids.
What happens to the buoyant force when a submerged object is pushed deeper into the fluid?- a) It decreases
- b) It increases
- c) It disappears
- d) It remains constant
Correct answer is option 'B'. Can you explain this answer?
What happens to the buoyant force when a submerged object is pushed deeper into the fluid?
a)
It decreases
b)
It increases
c)
It disappears
d)
It remains constant
|
|
Arien Instructors answered |
When a submerged object is pushed deeper into a fluid, the buoyant force increases. This is due to the increase in pressure at greater depths, which results in a greater upward force acting on the submerged object. This principle is essential for understanding why certain objects float or sink depending on their depth in the fluid.
Which statement best describes the center of buoyancy for a submerged object?- a) Always above the center of gravity
- b) Coincides with the center of gravity for all objects
- c) Always below the center of gravity
- d) Changes with the object's orientation
Correct answer is option 'C'. Can you explain this answer?
Which statement best describes the center of buoyancy for a submerged object?
a)
Always above the center of gravity
b)
Coincides with the center of gravity for all objects
c)
Always below the center of gravity
d)
Changes with the object's orientation
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Arien Instructors answered |
The center of buoyancy for a submerged object is always located above the center of gravity for a floating object. This positioning contributes to the stability of the object in the fluid. If the center of buoyancy is below the center of gravity, it helps maintain equilibrium and prevents the object from tipping over.
What is the upward force acting on a body immersed in a fluid called?- a) Buoyant force
- b) Gravitational force
- c) Weight
- d) Pressure force
Correct answer is option 'A'. Can you explain this answer?
What is the upward force acting on a body immersed in a fluid called?
a)
Buoyant force
b)
Gravitational force
c)
Weight
d)
Pressure force
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|
Arien Instructors answered |
The upward force acting on a body immersed in a fluid is known as the buoyant force or upthrust. This force is responsible for making objects float or sink in fluids. It arises due to differences in pressure exerted by the fluid on different parts of the submerged object. Understanding buoyancy is crucial in various applications, from designing ships to understanding how swimmers float.
What is the unit of buoyant force?- a) Pascal (Pa)
- b) Kilogram (kg)
- c) Joule (J)
- d) Newton (N)
Correct answer is option 'D'. Can you explain this answer?
What is the unit of buoyant force?
a)
Pascal (Pa)
b)
Kilogram (kg)
c)
Joule (J)
d)
Newton (N)
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Arien Instructors answered |
The unit of buoyant force is the Newton (N). This is the standard unit of force in the International System of Units (SI). Buoyant force is calculated based on the volume of fluid displaced and the density of the fluid, following the equation \(F_B = V \cdot \rho \cdot g\).
What is the principle behind determining the relative density of a solid using Archimedes' principle?- a) Ratio of mass to volume
- b) Volume of the solid divided by the volume of water displaced
- c) Weight of the solid in water divided by the weight of a known mass
- d) Weight of the solid in air divided by the loss of weight in water
Correct answer is option 'D'. Can you explain this answer?
What is the principle behind determining the relative density of a solid using Archimedes' principle?
a)
Ratio of mass to volume
b)
Volume of the solid divided by the volume of water displaced
c)
Weight of the solid in water divided by the weight of a known mass
d)
Weight of the solid in air divided by the loss of weight in water
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Arien Instructors answered |
The principle behind determining the relative density of a solid using Archimedes' principle involves calculating the weight of the solid in air divided by the loss of weight when submerged in water. This method allows for the comparison of the solid's density to that of water, providing a straightforward means to assess buoyancy and material properties.
Which principle explains why a hydrogen-filled balloon rises in air?- a) Law of Conservation of Mass
- b) Archimedes' Principle
- c) Pascal's Principle
- d) Bernoulli's Principle
Correct answer is option 'B'. Can you explain this answer?
Which principle explains why a hydrogen-filled balloon rises in air?
a)
Law of Conservation of Mass
b)
Archimedes' Principle
c)
Pascal's Principle
d)
Bernoulli's Principle
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Arien Instructors answered |
A hydrogen-filled balloon rises in air due to Archimedes' Principle, which states that an object will float if the buoyant force acting on it is greater than its weight. In this case, the weight of the air displaced by the balloon is greater than the weight of the balloon itself, allowing it to rise.
How does the principle of floatation apply to large ships compared to small objects like nails?- a) Ships are made of lighter materials
- b) Ships are always heavier than nails
- c) Nails are designed to float
- d) Ships have a greater volume and displace more water
Correct answer is option 'D'. Can you explain this answer?
How does the principle of floatation apply to large ships compared to small objects like nails?
a)
Ships are made of lighter materials
b)
Ships are always heavier than nails
c)
Nails are designed to float
d)
Ships have a greater volume and displace more water
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Arien Instructors answered |
The principle of floatation applies to large ships compared to small objects like nails because ships have a greater volume and can displace more water, which generates a larger buoyant force. Although ships are made of materials that are denser than water, their design allows them to float due to the significant volume of water they displace, balancing their weight.
Chapter doubts & questions for Upthrust In Fluids, Archimedes' Principle And Floatation - Physics Class 9 ICSE 2025 is part of Class 9 exam preparation. The chapters have been prepared according to the Class 9 exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Class 9 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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Physics Class 9 ICSE
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