Pressure, It’s unit and applications

Pressure, It’s unit and applications

What is Pressure?

The Force acting on a unit area of a surface is called pressure.

Pressure = Force/Area P=F/A SI unit of pressure : N/m = Pascal = Pa

Pressure is inversely proportional to the area. It means that if area of any body increases pressure will be decrease and If area of any body decreases then pressure will be increase.

Some examples of Pressure:-

• Heavy bag have wide shoulder pad so that pressure will reduce on the shoulder of the person carrying the bag.
• Sharp knife has very small Surface area that’s by it exert high pressure on meat to cut it.
• Skis have a large area to reduce the pressure on the snow. This ensures that the skis do not sink into the snow too far.
• Ink is filled in the pen because of atmospheric pressure.
• Inflating a Bicycle Tire: Using a hand pump to increase the pressure inside a bicycle tire.
• Drinking from a Straw: Applying suction to draw liquid through a straw involves creating a pressure difference.
• Using a Hydraulic Jack: Lifting a car with a hydraulic jack by increasing the pressure in the hydraulic fluid.
• Breathing: Inhaling and exhaling involve changes in air pressure in your lungs.
• Filling a Water Bottle: Closing the cap on a water bottle creates pressure inside the bottle, keeping the liquid from spilling.
• Sitting on a Chair: Your body exerts pressure on the chair due to your weight.
• Blowing up a Balloon: Inflating a balloon by blowing air into it increases the air pressure inside.
• Pushing a Cart: When you push a shopping cart, you apply force, which creates pressure on the wheels.
• Using a Squeeze Bottle: Squeezing a condiment bottle increases the pressure, causing the sauce to come out.
• Diving into a Pool: As you dive into a pool, the water pressure changes with depth, affecting your ears and body.

Types of pressure:-

• Atmosphere pressure
• Absolute pressure
• Gauge pressure
• Differential pressure

Pressure in liquid

A liquid exerts pressure on the wall of container equal to the weight of liquid.

Pressure in liquid = ρgh Where, ρ= density g= gravitational acceleration h= depth

Characteristics of pressure in a liquid:-

• The intensity of pressure depend only on the vertical height of the standing fluid. It means that at a particular depth pressure acts equally in all directions.
• The intensity of pressure is independent of the shape of the container and it’s inclination because pressure is unit area measurement of weight of fluid particles.

Frequently Asked Questions:

 

1. The SI unit of pressure is_______.

A) Pascal
B) Joule
C) Newton
D) Watt

ANSWER= (A) Pascal
Explain:-
Check Answer

 

2. The force on unit area is called______.

A) Volume
B) Pressure
C) Mass
D) Density

ANSWER= (B) Pressure
Explain:-
Check Answer

 

3. The pressure exerted by liquid____.

A) decrease with depth
B) Remains constant
C) Increases with depth
D) any of the above

ANSWER= (C) Increases with depth
Explain:-
Check Answer

 

4. Atmospheric pressure is measured by______.

A) Barometer
B) Thermometer
C) Hygrometer
D) Anemometer

ANSWER= (A) Barometer
Explain:-
Check Answer

 

5. The atmospheric pressure at sea level is____.

A) 103kN/m^2
B) 10.3 m of water
C) 760 mm of mercury
D) all of these

ANSWER= (D) All of these
Explain:-
Check Answer

 

6. The formula for pressure in liquids is:

A) ρ/gh
B) ρg/h
C) ρgh
D) gh/ρ

ANSWER= (C) ρgh, where h is height, ρ is density and g is gravity
Explain:-
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7. Amount of pressure of liquid increases with:

A) depth
B) area
C) mass
D) volume

ANSWER= (A) depth
Explain:-
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8. Force acting on a smaller area exerts_______ pressure.

A) less
B) same
C) No pressure
D) High

ANSWER= (D) High Pressure
Explain:-
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9. Instrument used to measure pressure of gases or liquids is called_____.

A) Barometer
B) Payrometer
C) Galvanometer
D) Manometer

ANSWER= (D) Manometer
Explain:-
Check Answer

 

10. Atmospheric pressure at sea level equals:

A) 1.01 × 10^2 Pascal
B) 1.01 × 10^3 Pascal
C) 1.01 × 10^5 Pascal
D) 1.01 × 10^6 Pascal

ANSWER= (C) 1.01 × 10^5 Pascal
Explain:-
Check Answer

Read Also-

• Fundamental quantities and its units
• Force, its types and its units
• Motion and it’s type
• Surface Tension and it’s applications
• Explanations of elasticity and Hooke’s law
• Heat transfer and Modes of heat transfer

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