Tag: pressure on surface

Questions Related to pressure on surface

Which of the following describe $Pressure$ correctly?

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. $Pressure=\dfrac{Work}{Volume}$

  2. $Pressure=Work \times Volume$

  3. $Pressure=\dfrac{Force}{Volume}$

  4. None of these

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Correct Option: A
Explanation:

$Pressure=\frac{Force}{Area}=\frac{Force \times Distance}{Area \times Distance}=\frac{Work}{Volume}$

Unit of Pressure is a

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. direct unit

  2. derived unit

  3. complex unit

  4. none of these

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Correct Option: B
Explanation:

Unit of Pressure, $Pa$ (in SI) is derived from the units of Force ($N$ in SI) and Area ($m^2$ in SI).
$Pa=\dfrac{N}{m^2}$
So, it is a derived unit.

For constant $Pressure$

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. $Force \propto Area$

  2. $Force \propto \frac{1}{Area}$

  3. $Force \propto Area^2$

  4. None of these

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Correct Option: A
Explanation:

$Pressure=\dfrac{Force}{Area}=Constant$


$\therefore$ $Force=Constant \times Area$

Or, $Force \propto Area$

When the temperature of atmosphere rises,

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. Density of air increases.

  2. Atmospheric pressure decreases.

  3. Both A and B.

  4. None

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Correct Option: B
Explanation:

With the increase in temperature, the density of atmosphere decreases, hence the atmospheric pressure decreases.

Fill in the blank.

Pressure is the force acting _________ on a unit area of object

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. Perpendicularly

  2. Parallel

  3. Diagonally

  4. All

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Correct Option: A
Explanation:

Pressure is defined as force per unit area. The standard unit for pressure is the Pascal, which is a Newton per square meter.

$P=\dfrac{F}{A}$

Here the force acts perpendicularly on the area. 

As the moisture present in the air increases,

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. Density if air increases.

  2. Atmospheric pressure decreases.

  3. Both A and B

  4. None

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Correct Option: B
Explanation:
The increased moisture in density suggests the decrease in its density and hence the atmospheric pressure also decreases.

Effect of a force depends on the

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. Volume of the object on which the force acts

  2. Area of the object on which the force acts

  3. Displacement caused by the force

  4. None

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Correct Option: B
Explanation:

Pressure is a measure of effect of force on an object.

Pressure is defined as force per unit area, that is,
$P=\dfrac{F}{A}$
Hence the effect of force depends upon the area upon which it acts. Smaller area would have greater effect for equal amount of applied force.

Pressure exerted on a surface depends on
physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. Thrust

  2. Area on which thrust is applied.

  3. Both A and B

  4. None

Show answer
Correct Option: C
Explanation:

Pressure can be defined as force per unit area i.e. $\dfrac{Force}{Area}$. 

Hence pressure is depends on thrust (force) and the area on which the force acts (area on which thrust is applied)

As altitude increases, atmospheric pressure

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. increases.

  2. decreases.

  3. remains constant.

  4. None.

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Correct Option: B
Explanation:

The atmospheric pressure exists due to weight of the atmosphere above it. 
As the altitude increases, the amount of atmosphere above, and hence its weight, and hence the atmospheric pressure decreases.

Which of the following ratio expresses pressure?

physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

  1. Force/area

  2. Energy/volume

  3. Energy/area

  4. Force/volume

Show answer
Correct Option: A
Explanation:

We know that pressure is the force per unit area. 

So pressure $=force/area$