Why in NEWS
Hydraulic systems are at the core of machines that lift, press, steer, and land, from tower cranes to aircraft gears. Their ability to multiply force makes them essential in engineering, aviation, agriculture, and transport.
They work on a simple but powerful physics principle—Pascal’s Law, allowing small efforts to move huge loads.
Key Concepts
| Term/Concept | Description |
|---|---|
| Hydraulic System | A system that uses incompressible fluids (usually oil) to transmit force from one point to another. |
| Pascal’s Law | States that pressure applied to a confined fluid is transmitted equally in all directions. |
| Pressure (Pa) | Force per unit area. 1 Pascal = 1 Newton/m². Remains constant throughout the fluid in a closed hydraulic system. |
News in Simple Terms
- A small input force applied at one piston is transferred through oil to another piston with larger area, resulting in greater output force.
- This principle is widely used in construction, vehicles, aircraft, factories, and even farming machinery.
- The key advantage is achieving high force output with minimal effort—with smooth and precise motion.
How Hydraulic Systems Work
| Step | Explanation |
|---|---|
| Force Applied | A small force is applied to a piston in a fluid-filled chamber. |
| Fluid Transmits Force | Since oil is incompressible, the force is instantly transmitted through the system. |
| Output Piston Moves | The pressure pushes a larger piston, producing a greater output force (based on area difference). |
Applications of Hydraulic Systems
| Sector | Uses |
|---|---|
| Construction | Excavators, bulldozers, cranes |
| Automotive | Brakes, clutches, power steering |
| Aviation | Landing gear, flaps, brakes |
| Industry | Hydraulic presses, lifts, molding machines |
| Agriculture | Tractors, harvesters, plows |
Advantages of Hydraulic Systems
| Advantage | Description |
|---|---|
| High Force with Small Input | Amplifies force efficiently. |
| Smooth Movement | Enables precise and controlled motion. |
| Compact Design | High power-to-weight ratio. |
| Good Heat Dissipation | Suitable for continuous heavy-duty operations. |
In a Nutshell
Memory Code: “HYPER”
H – High force output
Y – Used in wide sectors
P – Pascal’s Law-based
E – Efficient and smooth operation
R – Reliable for heavy machinery
Prelims Practice Questions
- What principle does a hydraulic system primarily operate on?
A. Archimedes’ Principle
B. Newton’s Third Law
C. Pascal’s Law
D. Bernoulli’s Principle - In a hydraulic system, if the pressure is kept constant, what can be done to increase the output force?
A. Increase temperature
B. Decrease fluid density
C. Increase output piston area
D. Use a compressible fluid - Which of the following is NOT typically a hydraulic system application?
A. Elevator lifts
B. Aircraft landing gear
C. Bicycle pedal mechanism
D. Bulldozers
Prelims Answers with Explanation
| Q No. | Answer | Explanation |
|---|---|---|
| 1 | C | Hydraulic systems are based on Pascal’s Law. |
| 2 | C | Output force = pressure × area. More area means more force. |
| 3 | C | Bicycles use mechanical—not hydraulic—systems. |
