Tag: upthrust in fluids, archimedes' principle and floatation

Questions Related to upthrust in fluids, archimedes' principle and floatation

An iron needle sinks in water as its density is less than 1 $ \displaystyle g/cm^{3} $.

physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. True

  2. False

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Correct Option: B
Explanation:

Any substance sinks in a liquid of density of S when density of substance is greater than that of liquid i.e.

$\boxed { density\quad of\quad substance\quad >\quad S } $

If a body X floats in liquid Y. The density of body X is greater than liquid Y. True or false

physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. True

  2. False

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Correct Option: B
Explanation:

For a body to sink in water then density of body should be more than density of water or any fluid i.e. density of body > density of water.

Submarine's lactometers, hydrometers, etc. are designed according to __________.

archimedes' principle and its applications archimedes' principle experimental verification of archimedes' principle upthrust in fluids, archimedes' principle and floatation physics

  1. Archimedes principle

  2. Principles of hydrology

  3. Principles of fluid flow

  4. All of the above

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Correct Option: A
Explanation:

Archimedes principle was an important work and has many application. It is used for designing submarines, ships etc. lactometer and hydrometer and also based on this principle and are used to check the purity of milk and density of liquids respectively.

Archimedes' principle states that the buoyant force applied to an object 

physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. is greater the weight of the fluid the object displaces

  2. is equal to the weight of the fluid the object displaces

  3. is less than the weight of the fluid the object displaces

  4. is zero

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Correct Option: B
Explanation:

Archimedes' principle states that the buoyant force applied to an object is equal to the weight of the fluid the object displaces.

Archimedes principle works when the body is
physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. Partially immersed in a liquid

  2. Fully immersed in a liquid

  3. Both A and B

  4. This principle has nothing to do with the level of immersion of the body
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Correct Option: C
Explanation:

Archimedes' Principle states that buoyant force acting on body upwards is equal in magnitude of the weight of liquid it displaces. Depending upon how much the body is immersed in liquid, and hence how much the weight of liquid is displaced, the buoyant force varies.

When an object is immersed in water, it displaces $20\,kg$ of water. How much is the buoyant force acting on the object in Newtons?
physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. $100$

  2. $200$

  3. $0$

  4. $400$

Show answer
Correct Option: B
Explanation:

According to the Archimedes principle, the buoyant force acting on an object immersed in liquid is equal to the weight of liquid it displaces. Hence the buoyant force acting on the given object=$20kg\times 10m/s^2=200N$

Magnitude of buoyant force is given by 
physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. Newton's first law

  2. Archimedes principle
  3. Newton's second  law

  4. None of the above 

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Correct Option: B
Explanation:

Archimedes principle, states that any body completely or partially submerged in a fluid (gas or liquid) at rest is acted upon by an upward, or buoyant force the magnitude of which is equal to the weight of the fluid displaced.

Archimedes principle is used for
physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications
  1. Determining the force applied on the object
  2. Determining the relative density of the object
  3. Determining the gravitational constant

  4. All the above

Show answer
Correct Option: B
Explanation:
Hydrometer works on the Archimedes principle. The level at which it floats in liquid determines its relative density.
Quantitatively, $V _0dg=V _{immersed}\rho g$

$\implies $ relative density $\rho _r=\dfrac{d}{\rho}=\dfrac{V _{immersed}}{V _0}$
Fill in the blank.
It is the ______ which makes balloon to rise in air. 
physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. Upthrust

  2. Buoyant force

  3. Both A and B

  4. None

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Correct Option: C
Explanation:

A balloon is filled with air at high pressure which leads to uprising of it because it experiences more buoyant force or we can say upthrust as they are same in this case.

Lactometers are based on
physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

  1. Third law of motion

  2. Kepler's law

  3. Acceleration due to gravity

  4. Archimedes principle

Show answer
Correct Option: D
Explanation:

Lactometer works on the Archimedes' Principle that a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced. If the milk sample is pure, then the lactometer floats on it and if it is adulterated or impure, then the lactometer sinks.