Test: Pascal's Principle - 2 - EmSAT Achieve MCQ

Concept:

The ratio of force applied in ram to the area of ram is equal to ratio of force applied in plunger to the area of plunger, as the pressure intensity is same.

Calculation:

Pascal Law:

Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.

This follows that pressure at any point in a fluid at rest has the same magnitude in all directions.

Uses: This law is used in hydraulic lifts and hydraulic brakes in cars.

Concept:

Pascal’s Law:

• It was given by Blaise pascal
• It is also known as the principle of transmission of fluid pressure
• It states that the pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.
• Alternate definition:- The pressure applied to any part of the enclosed liquid will be transmitted equally in all directions through the liquid.

Applications:

• The underlying principle of hydraulic jack and hydraulic press.
• Force amplification in the braking system of most motor vehicles.
• Used in artesian wells, water towers, and dams.

Calculation:

Given:

Diameter of plunger, d = 3 cm, Diameter of ram, D = 20 cm, Force required at the plunger = ?, Weight = 30 kN

According to pascals law,

Pressure applied at ram = Pressure exerted on the plunger

Here, F₂ = force required on the plunger

Pascal’s law: Pascal’s Law is the principle of transmission of fluid-pressure, It says that "a pressure exerted anywhere in a point of the confined fluid is transmitted equally in all directions throughout the fluid”.

Concept:

• Pascal’s principle: Pascal’s Law is the principle of transmission of fluid-pressure.
  • It says that "a pressure exerted anywhere in a point of the confined fluid is transmitted equally in all directions throughout the fluid”.

EXPLANATION:

1. Centrifuge: Centrifugation is used to separate the contents of mixtures according to their size and density. The centrifuge works on the principle of sedimentation.
2. Hydraulic Lift: The lift that uses pascal's law and used to lift objects with the help of fluid is called hydraulic lift.  It works on Pascal's law. So option 2 is correct.
3. ​Motor: A motor is an electrical device that converts electrical energy into mechanical energy. It works on the principle that a current-carrying conductor experiences a mechanical force when it is placed in a magnetic field.
4. Lever: A lever is a simple machine that is made up of two load arms and a fulcrum. The distance from the fulcrum can be used to determine how the input and output forces are related to each other.

Concept:

Pascal’s Law:

• It was given by Blaise pascal
• It is also known as principle of transmission of fluid pressure
• It states that the pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.
• Alternate definition:- The pressure applied to any part of the enclosed liquid will be transmitted equally in all directions through the liquid.

Applications:

• The underlying principle of hydraulic jack and hydraulic press.
• Force amplification in the braking system of most motor vehicles.
• Used in artesian wells, water towers and dams.

Calculation:

Given:

Diameter of plunger, d = 1.5 cm, Diameter of ram, D = 15 cm, weight exerted on the ram, F1 = 1000 kg

According to pascals law,

Pressure applied at plunger = Pressure exerted on the ram

Here, F₂ = force required on the plunger

The correct answer is Pascal's law.

• The Pascal's law states that in a fluid which is at rest in a container, the pressure applied to one part of the fluid is uniformly transmitted to all the parts of the fluid.

Key Points

• A hydraulic lift employs this principle to lift heavy objects.
• When pressure is applied to a fluid through one piston, it results in an equivalent pressure on another piston in the system which is then able to lift objects.
• With the increase in the area of the second piston, the force exerted by it also increases thus enabling lifting of heavier objects.

Additional Information

• Hooke's law states that force needed to extend or compress a spring by some distance is directly proportional to that distance.
• Newton's first law of motion - A body at rest remains at rest, or if in motion, remains in motion at constant velocity unless acted on by a net external force. 
• Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

Newtonian fluids:

• Newtonian fluids defined as fluids for which the shear stress is linearly proportional to the shear strain rate
• Newtonian fluids are analogous to elastic solids (Hooke’s law: stress proportional to strain)
• Any common fluids, such as air and other gases, water, kerosene, gasoline, and other oil-based liquids, are Newtonian fluids

Non-Newtonian fluid:

• Fluids for which the shear stress is not linearly related to the shear strain rate are called non-Newtonian fluids examples include slurries and colloidal suspensions, polymer solutions, blood, paste, and cake batter

Ideal fluid:

• Fluids which don’t have viscosity and are incompressible are termed as an ideal fluid such fluid do not offer shear resistance i.e no resistance is encountered as the fluid moves. In ideal fluid, the pressure at a point is the same in all direction.

Real fluid:

• Fluids which do possess viscosity are termed as real fluids. These fluids always offer shear resistance i.e. Certain amount of resistance is always offered by these fluids as they move.

Hence in practical life, ideal fluid does not exist. It is an imaginary fluid taken into consideration to compare with all other fluids to check how close they are to the ideal fluid.

Concept:

Pascal’s Law:

• It was given by Blaise pascal
• It is also known as the principle of transmission of fluid pressure
• It states that the pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.
• Alternate definition:- The pressure applied to any part of the enclosed liquid will be transmitted equally in all directions through the liquid.

Applications:

• The underlying principle of hydraulic jack and hydraulic press.
• Force amplification in the braking system of most motor vehicles.
• Used in artesian wells, water towers, and dams.

Calculation:

Given:

Diameter of plunger, d = 3 cm, Diameter of ram, D = 30 cm, Force required at the plunger = ?, Weight = 30 kN

According to pascals law,

Pressure applied at ram = Pressure exerted on the plunger

Here, F₂ = force required on the plunger

Pascal’s principle: 

• Pascal’s Law is the principle of transmission of fluid pressure.
• It says that "a pressure exerted anywhere in a point of the confined fluid is transmitted equally in all directions throughout the fluid”.