# MHT-CET Physics Crash Course “Pascal’s Law Hydraulic Press” Class 12

## “Pascal’s Law Hydraulic Press” MHT-CET Class 12 Physics Crash Course| Chapter Mechanical Properties of Fluids

In this session G.S. Khairnar discussed the theory and MCQ’s of “Pascal’s Law Hydraulic Press”. The session will be useful for all the aspirants of MHT-CET 2022. The session will be in Marathi and English.

### Pascal’s Law Hydraulic Press:-

Hello students, in previous article we have learnt about the concept of pressure. In this article we are going to learn the details about the law related to pressure i.e. Pascal’s law.

Consider the following examples,

1. While taking injection, doctor/nurse applies the force on the piston and the medicine in the syringe get injected in vein
2. To dig a hole or to demolished the old buildings JCB’s are used, in which the operator applies the force on piston which exerts the pressure on the object

In above examples, the force acting on the piston exerts the pressure. This pressure is transmitted equally or unequally in the system? Let’s learn about this in the article below.

Let’s learn the concept of Pascal’s law in detail…!

Statement:

The pressure applied to any part of fluid at rest is transmitted equally in all parts of the fluid without diminished.

Explanation:

Consider the vessel containing fluid at rest and the pressure gauge meter are fixed at different points as shown in fig above.

The magnitude of force acting on the given areas may be different from point to point but the magnitude of pressure always remains same.

In the figure according to Pascal’s law, the pressure reading in all the gauge meter will be same so that,

Let’s study applications of Pascal’s law……!

Hydraulic press:

It is used to press cotton bales, extract oil from oil seed is based on Pascal’s law. It contains the tank of water with two openings of different cross sectional areas A1 and A2 such that A1>A2. Opening A2 has one piston termed as input piston. Thick metal and movable plate is fixed at opening A1 taken as output piston and then allowed to strike on another plate(wall) as shown in fig below,

Force of magnitude F2 is applied on input piston of area A2, which exerts pressure P2 on the liquid in the tank. This pressure is transmitted to the output piston of area A1 exerts force F1.

The pressures on the pistons can be written as,

Hence force on output piston is greater that the force on input piston which helps to press or crush the things kept on metal plate.

### Let’s solve the following MCQ’s…

Q.1) According to Pascal’s law…..

a) pressure applied to fluid at rest becomes zero after transmission

b) pressure applied to fluid at rest transmitted unequally to all parts of fluid

c) pressure applied to fluid at rest transmitted equally to all parts of fluid

d) all of these

Answer

c) pressure applied to fluid at rest transmitted equally to all parts of fluid

Q.2) Doctor advised you to take the injection for instant relief; the working of syringe is based on…..

a) Boyle’s law

b) Pascal’s law

c) Charles’s law

d) Dalton’s law of partial pressure

Answer

b) Pascal’s law

Q.3) Which among the following mechanical process based on Pascal’s law…..

a) Hydraulic lift

b) Escalators

c) Disc brakes

d) Magnetic brakes

Answer

a) Hydraulic lift

Q.4) Extraction of oil from oil seeds, pressing of cotton bales can be done with the help instrument that based on Pascal’s law is…..

a) Magnetic press

b) Electric press

c) Hydraulic press

d) None of these

Answer

c) Hydraulic press

Q.5) Driver applies the force of 2000 N on a brake pedal of hydraulic brakes of area 5cm2, force required on brake drums of area 10 cm2 to stop the vehicle is…..

a) 1000 N

b) 2000 N

c) 3000 N

d) 4000 N

Answer

d) 4000 N

Q.6) Ratio of areas of input piston to output piston is 3:4, the ratio of forces on the pistons is …..

a) 3:4

b) 4:3

c) 2:1

d) 1:2

Answer

a) 3:4

By Pascal’s law

### ♦जिल्हा नुसार जाहिराती ♦

अहमदनगर अकोला अमरावती औरंगाबाद भंडारा बुलढाणा
चंद्रपुर धुले गढ़चिरौली गोंदिया हिंगोली जलगांव
जालना कोल्हापुर लातूर मुंबई नागपुर नांदेड़
नंदुरबार नाशिक उस्मानाबाद पालघर परभानी पुणे
रायगढ़ रत्नागिरि सांगली सातारा सिंधुदुर्ग सोलापुर
ठाणे वर्धा वाशिम यवतमाल बीड

### ♦शिक्षणानुसार जाहिराती ♦

७ वी (7th) दहावी (SSC) बारावी (HSC) डिप्लोमा आय.टी.आय पदवी
पदव्युत्तर शिक्षण बी.एड एम.एड एल.एल.बी / एल.एल.एम बीएससी एमबीए
बीसीए एमसीए बी.कॉम एम.कॉम GNM/ANM एमएससी
बी.फार्म एम.फार्म बी.ई एम.ई BAMS/BHMS एम.बी.बी.एस / एम.डी
बी.टेक एम.टेक MS-CIT