Types of Equilibrium – What is Equilibrium? – eSaral

Hey, Do you want to learn about the Types of Equilibrium? If so. Then you are at the right place. 

What is Equilibrium? 

A body is said to be in translatory equilibrium if the net force acting on the body is zero, $\overrightarrow{\mathrm{F}}_{\text {net }}=0$

If the force are conservative then $\mathrm{F}=-\frac{\mathrm{dU}}{\mathrm{dr}}$

For equilibrium F = 0.

So, $-\frac{d U}{d r}=0$



At equilibrium position slope of U-r graph is zero or the potential energy is optimum (maximum or minimum or constant).

Types of Equilibrium.

  1. Stable Equilibrium
  2. Unstable Equilibrium
  3. Neutral Equilibrium

Stable Equilibrium:

When a particle is slightly displaced from equilibrium and it tends to come back towards equilibrium then it is said to be in stable equilibrium

Unstable Equilibrium:

When a particle is displaced from equilibrium and it tends to move away from equilibrium position then it is said to be in unstable equilibrium

Neutral Equilibrium:

When a particle is displaced from equilibrium and no force acts on it then the equilibrium is said to be neutral equilibrium


The situation where F = 0 and $\frac{\mathrm{d} \mathrm{U}}{\mathrm{dr}}=0$ can be obtained under three conditions.

Types of Equilibrium

Three identical balls are placed in equilibrium in positions as shown in fig. (a), (b), and (c) respectively.

  1. The ball is placed inside a smooth spherical shell. This ball is in a stable equilibrium position.
  2. The ball is placed over a smooth sphere. This is in the Unstable equilibrium position.
  3. The ball is placed on smooth horizontal ground. This ball is in the Neutral equilibrium position.

Difference Between Stable, Unstable, and Neutral Equilibrium

S.no Stable equilibrium Unstable equilibrium Neutral equilibrium
1 Net force is zero Net force is zero Net force is zero
2 $\frac{d U}{d r}=0$ or slope of $U-r$ graph is zero $\frac{\mathrm{dU}}{\mathrm{dr}}=0$ or slope of U-r graph is zero. $\frac{\mathrm{dU}}{\mathrm{dr}}=0$ or slope of U-r graph is zero.
3 When displaced slightly, from its equilibrium position a net restoring force starts acting on the body which has a tendency to bring the body back to its equilibrium position. When displaced slightly from its equilibrium position, a net force starts acting on the body which moves the body in the direction of displacement or away from the equilibrium position. When displaced slightly from its equilibrium position the body has neither the tendency to come back to original position nor to move away from the original position.
4 Potential energy in equilibrium position is minimum as compared to its neighboring
points or $\frac{\mathrm{d}^{2} U}{\mathrm{dr}^{2}}=$ positive
Potential energy in equilibrium position is maximum as compared to its neighboring points
or $\frac{d^{2} U}{d r^{2}}=$ negative
Potential energy remains constant even if the body is displaced from its equilibrium position.
or $\frac{d^{2} U}{d r^{2}}=0$
5 When displaced from equilirbium position the centre of gravity of the body
goes up.
When displaced from equilibrium position the centre of gravity of the body comes down. When displaced from equilibrium position the centre of gravity of the body remains at the same level.


So, that’s all from this article. If you found this Explanation of Types of Equilibrium helpful then please share it with your friends.

For a better understanding of this chapter, please check the detailed notes of the Work Energy and Power. To watch Free Learning Videos on physics by Saransh Gupta sir Install the eSaral App.



neet 2020
NEET 2020 | Exam Pattern, Important dates, Application Form, Eligibility
NEET Application Form 2020 is going to release in the months of December. National Eligibility cum Entrance Test or NEET (previously known as AIPMT) is the national-level Medical Entrance exam for the aspirants to get admission in MBBS/BDS Courses in various government or private medical colleges affiliated by Medical Council of India. Get the Following details about NEET 2020 here: Examination Mode Important Dates How to Apply? Application Fee Eligibility Criteria Correction in Application Language Choices Exam Pattern NEET 2020 Syllabus NEET Counselling    Recently, the Ministry of Health announced that admission to MBBS courses in medical colleges across the country including JIPMER and all the AIIMS will be through the common national entrance test NEET. So, AIMS and JIPMER are no longer to be held.  

Examination Mode

As per the latest notice, NTA has cleared that NEET 2020 will take place in offline mode only!  

Important Dates for NEET 2020

Release of NEET application form 2020 December 2, 2019
Deadline to register for NEET 2020 December 31, 2019
NTA NEET admit card 2020 March 27, 2020
NEET 2020 exam May 3, 2020
NEET Result 2020 June 4, 2020

How to Apply?

  Step 1: Visit the official site of NTA www.ntaneet.nic.in Click on “Apply online” of application form link.   Step 2: Candidates need to register online  Official website – www.ntaneet.nic.in To complete the registration process, he/she will have to enter a valid email Id and phone number.   Step 3: Completing the NEET 2020 application Post completion of the registration process, the registration Id and password generated will be sent to the registered email Id and mobile number of the candidate. He/she has to use these login credentials to access the application form of NEET 2020. To complete the form, he/she has to fill in the required personal details, academic details, exam centre preference, etc.   Step 4: Uploading scanned images Candidates have to upload the scanned image of a recent passport-sized photograph and signature. These have to be in JPG/JPEG format only.   Step 5: Application fee NEET 2020 application form cannot be submitted without paying the prescribed non-refundable application fee. Candidates who belong to the general or OBC category have to pay an application fee of Rs 1400, whereas those belonging to the reserved categories such as ST/SC/PWD have to pay Rs 750.   Step 6: Print the confirmation page Candidates are advised to keep a copy of the filled application and payment receipt for future use.

Application fee

NEET 2020 application form cannot be submitted without paying the prescribed non-refundable application fee.
  • General or OBC category have to pay an application fee of Rs 1400,
  • Reserved categories such as ST/SC/PWD have to pay Rs 750.

Eligibility Criteria:



Indian, Persons of Indian Origin (PIOs), Overseas Citizens of India (OCIs), Foreign Nationals and Non-resident Indians (NRIs) candidates will be considered as eligible and can fill up the NEET 2020 application form.  

Age Limit

The Minimum age limit (General Category) to apply for NEET 2020 exam should be 17 Years. However, the maximum age limit is 25 Years.   Candidates belonging to SC/ST/OBC/PH should have their birthdate between 07.05.1988 and 01.01.2002.  

Age Relaxation

Category Age Relaxation
SC/ST/OBC/PH 05 Years of Age Relaxation

Educational Qualification Criteria:

To apply for NEET exam 2020, you must have passed Higher Secondary Examination (12th board examination) with Chemistry, Physics, and Biology/ Biotechnology with minimum 50% marks in each subject. Candidates from National Institute of Open Schooling (NIOS) or any State Open School are also eligible to apply. Note: Candidates appearing in the qualifying exam can also apply for NEET 2020 exam.

Correction in Application Form

Correction Date for NEET Application: The application form correction for NEET 2020 exam will start from January 1st Week, 2019 (tentative). NEET Application Correction Procedure: A form will be provided for correction facility such as uploading images, signature, etc. Please note that this is a onetime opportunity, so use this chance carefully. To make the changes, visit the official site, now click on the ‘candidate’s login’. Submit your registration number and password. Now click on the form correction link, make changes and submit the form.  

Language Choices

You will get the question paper in the following languages: Hindi, English, Assamese, Urdu, Telugu, Tamil, Gujarati, Marathi, Oriya, Kannada and Bengali.  

Exam Pattern:

The exam includes questions from Physics, Chemistry and Biology curriculum of class XI and XII. Both Physics and Chemistry have 45 questions each. Biology has 90 questions divided equally among Botany and Zoology. The paper will have only multiple-choice questions. 1 mark will be deducted for every incorrect answer. For each correct answer, 4 marks will be awarded. 45 questions are assigned to Physics, Chemistry, Botany and Zoology, each.


Number of Questions

Maximum Marks

Physics 45 180
Chemistry 45 180
Biology (Zoology +Botany) 90 (45+45) 360 (180+180)
Total 180 Questions 720 Marks

Syllabus of NEET 2020

Click HERE for Detailed Syllabus of NEET 2020.  

NEET Syllabus for Physics:

Class 11 Physical world and measurement Kinematics Laws of Motion Work, Energy and Power Motion of System of Particles and Rigid Body Gravitation Properties of Bulk Matter Thermodynamics Behaviour of Perfect Gas and Kinetic Theory Class 12 Electrostatics Current Electricity Magnetic Effects of Current and Magnetism Electromagnetic Induction and Alternating Currents Electromagnetic Waves Optics Dual Nature of Matter and Radiation Atoms and Nuclei Electronic Devices Oscillations and Waves  

NEET Syllabus for Chemistry:

Class 11 Some Basic Concepts of Chemistry Structure of Atom Classification of Elements and Periodicity in Properties Chemical Bonding and Molecular Structure States of Matter: Gases and Liquids Thermodynamics Equilibrium Redox Reactions Hydrogen s-Block Element (Alkali and Alkaline earth metals) Some p-Block Elements Organic Chemistry- Some Basic Principles and Techniques Hydrocarbons Environmental Chemistry Class 12 Solid State Solutions Electrochemistry Chemical Kinetics Surface Chemistry General Principles and Processes of Isolation of Elements p- Block Elements d and f Block Elements Coordination Compounds Haloalkanes and Haloarenes Alcohols, Phenols and Ethers Aldehydes, Ketones and Carboxylic Acids Organic Compounds Containing Nitrogen Biomolecules Polymers Chemistry in Everyday Life  

NEET Syllabus for Biology:

Class 11 Diversity in Living World Structural Organisation in Animals and Plants Cell Structure and Function Plant Physiology Human physiology Class 12 Reproduction Genetics and Evolution Biology and Human Welfare Biotechnology and Its Applications Ecology and environment Result Declaration The exam conducting authority NTA will release the NEET 2020 result on their official site on 4th June, 2020. You can get here the direct link to check the NEET result once it is out. Make sure you have the roll number and date of birth to access the result.  

Admission (through NEET 2020)

15% AIQ (All India Quota), 85% State Quota, 100% deemed & ESIC, Management/NRI, Central Pool, AFMC