Tag: pressure in fluids

Questions Related to pressure in fluids

Which of the following is true?

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. Fluid do not have any weight

  2. Only liquids have weight

  3. Only gases have weight

  4. Fluids have weight

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Correct Option: D
Explanation:

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

Pressure is exerted by fluids because of their weight. Static fluid pressure is exerted by the depth of the fluid, the density of the fluid and the acceleration of gravity.

Two stretched membranes of area $2 cm^2$ and $3 cm^2$ are placed in a liquid at the same depth. The ratio of the pressure on them is :

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. $1 : 1$

  2. $2 : 3$

  3. $3 : 2$

  4. $2^2 : 3^2$

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Correct Option: A
Explanation:

pressure depends on depth not on area so the two stretched membrane would  have  equal pressure.

so ratio of their pressures would be 1 : 1.
hence option (A) is correct

Fill in the blank

Fluids at a given depth exert ______ pressure in all directions 

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. same

  2. independent

  3. different

  4. zero

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Correct Option: A
Explanation:

Fluids at a given depth exert same pressure in all directions.
Pressure of a liquid is directly proportional to the depth, and for a given depth the liquid exerts the same pressure in all directions according to Pascal's law.

The most characteristic property of a liquid is :

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. elasticity

  2. fluidity

  3. formless

  4. volume conservation

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Correct Option: D
Explanation:

a liquid is  substance that flows freely but is of constant volume, having a consistency like that of water or oil.
The most characteristic feature is volume conserrvation.

A block of wood floats separately in river water and then in ocean water. Then the weight of the displaced river water is

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. equal to the weight of the displaced ocean water.

  2. less than the weight of the displaced ocean water.

  3. more than the weight of the displaced ocean water.

  4. not dependent on the density of the wooden block.

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Correct Option: A

The pressure exerted by liquid on container 

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. increases with depth

  2. decreases with depth

  3. remains unchanged with depth

  4. none of the above

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Correct Option: A
Explanation:

$\because p = h\times d\times d$
where, p = pressure
             h = depth
             d = density
so when depth is increases pressure is also increases.

The fluids in a confined space exert pressure in which direction?

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. Upward

  2. Downward

  3. Forward

  4. All directions

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Correct Option: D
Explanation:

Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same.

so option ( D) would be correct

Fill in the blank.

Liquids exerts pressure in _______ directions.

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. One

  2. Two

  3. All

  4. It do not extent any pressure

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Correct Option: C
Explanation:

Like solids fluids (liquids and gases) also exent pressure. A solid exent pressure only in the downward direction due to its weight, whereas liquids and gases exent pressure on the walls of their container.

If a sweet water fish enters a sea, the fish will

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. swell

  2. be squeezed

  3. remain as it is

  4. suffer none of these

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Correct Option: B
Explanation:

Liquid pressure is given by =$\rho \times g \times h$

The water from river has a lower density than the sea water. So, at equal depth, sweet water or river water exerts less pressure than sea water. Body of a sweet water fish is habituated with this lower pressure of river water. Naturally, when the fish will enter the sea, it will suffer greater pressure due to increase in density and hence the body of the fish will be squeezed slightly.

There are two fish tanks each of depth $0.5 m$. Base area of one is $0.5m^2$ and that of another is $0.1m^2$. At the depth of which tank will a fish feel larger pressure?

physics forces and matter pressure in fluids pressure in liquids introduction to pressure

  1. The tank of wider base area

  2. The tank of smaller base area

  3. Equal for both tanks

  4. Can't say

Show answer
Correct Option: C
Explanation:

Liquid pressure is given by =$ \rho \times g \times h$
Liquid pressure depends on the depth and not on surface area. Both the tanks have the same depth. So, for both the tanks, the fish will feel equal pressure.