•  
agra,ahmedabad,ajmer,akola,aligarh,ambala,amravati,amritsar,aurangabad,ayodhya,bangalore,bareilly,bathinda,bhagalpur,bhilai,bhiwani,bhopal,bhubaneswar,bikaner,bilaspur,bokaro,chandigarh,chennai,coimbatore,cuttack,dehradun,delhi ncr,dhanbad,dibrugarh,durgapur,faridabad,ferozpur,gandhinagar,gaya,ghaziabad,goa,gorakhpur,greater noida,gurugram,guwahati,gwalior,haldwani,haridwar,hisar,hyderabad,indore,jabalpur,jaipur,jalandhar,jammu,jamshedpur,jhansi,jodhpur,jorhat,kaithal,kanpur,karimnagar,karnal,kashipur,khammam,kharagpur,kochi,kolhapur,kolkata,kota,kottayam,kozhikode,kurnool,kurukshetra,latur,lucknow,ludhiana,madurai,mangaluru,mathura,meerut,moradabad,mumbai,muzaffarpur,mysore,nagpur,nanded,narnaul,nashik,nellore,noida,palwal,panchkula,panipat,pathankot,patiala,patna,prayagraj,puducherry,pune,raipur,rajahmundry,ranchi,rewa,rewari,rohtak,rudrapur,saharanpur,salem,secunderabad,silchar,siliguri,sirsa,solapur,sri-ganganagar,srinagar,surat,thrissur,tinsukia,tiruchirapalli,tirupati,trivandrum,udaipur,udhampur,ujjain,vadodara,vapi,varanasi,vellore,vijayawada,visakhapatnam,warangal,yamuna-nagar

Moment Of Inertia Of A Cylinder

Moment Of Inertia Of A Cylinder

The moment of inertia of a cylinder measures its resistance to rotational motion about an axis. It depends on mass distribution, radius, length, and axis position, and varies for solid and hollow cylinders due to different mass arrangements.

Moment of Inertia About Different Axes

Consider a cylinder of Mass M, Radius R, and Length L. It also depends on the position of the axis of rotation and the distribution of mass.

  • Solid Cylinder – mass is distributed throughout the volume.
  • Hollow Cylinder – mass is concentrated on the outer surface.

Solid Cylinder

Moment of Inertia About Central (Longitudinal) Axis

Derivation -

Divide the cylinder into many thin circular discs stacked along its length.

Moment of inertia of each disc about its central axis:

Derivation

Summing for all discs:

derivation

Therefore, the Moment of Inertia About the Central (Longitudinal) Axis is Axis

Moment of Inertia About Axis Perpendicular to Length and Passing Through Centre

This axis passes through the midpoint and is perpendicular to the length.

Using perpendicular axis and integration:

Axis

Hollow Cylinder

For a hollow cylinder (thin-walled), mass is distributed at a distance R from the axis.

Moment of Inertia About the Central Axis

All mass is at distance R, so:

Icentral axis = M R2

Moment of Inertia of a Thick Hollow Cylinder About the Central Axis

If the inner radius is R1 and the outer radius is R2:

Axis

Moment of Inertia About Axis Perpendicular to Length and Passing Through Centre

For a thin hollow cylinder:

Axis

For a thick hollow cylinder:

Axis(derived using integration)

Formulae At A Glance:

Shape Axis Moment of Inertia
Solid Cylinder Central axis along length MOI
Solid Cylinder Perpendicular through the centre MOI
Thick hollow cylinder Central axis MOI
Thin hollow cylinder Central axis MOI
Thin hollow cylinder Perpendicular through the centre MOI

Applications

  • Flywheels and rotors – Control speed fluctuations.
  • Pipes and gas cylinders – Stability during rotation.
  • Wheels and rollers – Design for vehicles and machinery.
  • Drums and conveyor rollers – Smooth industrial operations.
  • Rolling motion problems – Physics of rolling without slipping.

Summing Up

The moment of inertia of a cylinder represents its resistance to rotational motion, varying with shape (solid or hollow), radius, length, and axis position. Solid cylinders have mass distributed throughout, while hollow cylinders have mass on the outer surface. The concept is applied like flywheels, wheels, rollers, pipes, and drums for stability, motion control, and smooth industrial operations.

Frequently Asked Questions

Q1. Why is the moment of inertia higher for a hollow cylinder than for a solid cylinder of the same mass and radius?

The moment of inertia for a hollow cylinder is greater because more mass is concentrated farther from the axis.

Q2. Which cylinder, solid or hollow, rolls faster down an incline?

A solid cylinder rolls faster down an inclined plane because it has a smaller moment of inertia.

 

NEET Related Links

NEET Exam 

NEET  Exam Dates

NEET  Exam pattern

NEET  Syllabus

NEET  Eligibility Criteria

NEET  Application

NEET UG Counselling

NEET FAQ

NEET UG Result

NEET  Cut Off

JEE MAIN Related Links

JEE Main 

JEE Main Rank Predictor 

JEE Main College Predictor 

JEE Main  Exam Dates

JEE Main  Exam pattern

JEE Main  Application

JEE Main  Eligibility Criteria

JEE Main  Syllabus

JEE Main  Physics Syllabus

JEE Main  Maths Syllabus

JEE Main  Chemistry Syllabus

JEE Main  Admit Card

JEE Main  Counselling

JEE Main marks vs rank vs percentile

JEE Advanced Related Links

JEE Advanced  Exam Dates

JEE Advanced  Application

JEE Advanced  Eligibility Criteria

JEE Advanced  Syllabus

JEE Advanced  Maths Syllabus

JEE Advanced  Physics Syllabus

JEE Advanced  Chemistry Syllabus

JEE Advanced Exam Result

JEE Advanced Exam Dates

JEE Advanced Registration Dates

CUET Related Links

CUET  Eligibility Criteria

CUET  Admit Card

CUET  Exam Pattern

CUET  FAQs

CUET  Counselling

CUET  Syllabus

CUET  Result

CUET  Answer Key

CUET  Preparation

CUET CUTOFF

CUET  Application Form

Important Topics

Talk to Our Expert Request Call Back
Resend OTP Timer =
By submitting up, I agree to receive all the Whatsapp communication on my registered number and Aakash terms and conditions and privacy policy