Home
Class 11
PHYSICS
Statement-1: if moment of inertia of a r...

Statement-1: if moment of inertia of a rigid body is equal about two axis, then both the axis must be parallel.
Statement-2 from parallel axis theorem `I=I_(cm)+md^(2)`, where all terms have usual meaning.

A

Statement-1 is true, Statement-2: is true, Statement-2 is a correct explanation for Statement-1.

B

Statement-1 is true, Statement-2: is true, Statement-2 is NOT a correct explanation for Statement-1.

C

Statement-1 is true but statement-2 is false

D

Both statement 1 false and statement 2 are true.

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the given statements, we need to evaluate each one separately. ### Step 1: Understanding Statement-1 **Statement-1:** "If the moment of inertia of a rigid body is equal about two axes, then both the axes must be parallel." To understand this statement, we need to recall the definition of moment of inertia and how it varies with the choice of axes. The moment of inertia \( I \) of a rigid body depends on the axis about which it is calculated. If we have two different axes, the moment of inertia can be different unless certain conditions are met. ### Step 2: Applying the Parallel Axis Theorem The Parallel Axis Theorem states that: \[ I = I_{cm} + md^2 \] where: - \( I \) is the moment of inertia about the new axis, - \( I_{cm} \) is the moment of inertia about the centroidal axis, - \( m \) is the mass of the body, - \( d \) is the distance between the two axes. If the two axes are parallel, then the moment of inertia about the second axis can be calculated using this theorem. ### Step 3: Analyzing the Implications If the moment of inertia about two axes is equal, say \( I_1 = I_2 \), we can express this using the parallel axis theorem: \[ I_1 = I_{cm} + md_1^2 \] \[ I_2 = I_{cm} + md_2^2 \] Setting these equal gives: \[ I_{cm} + md_1^2 = I_{cm} + md_2^2 \] This simplifies to: \[ md_1^2 = md_2^2 \] Since \( m \) is the same for both axes, we can divide by \( m \): \[ d_1^2 = d_2^2 \] This implies that \( d_1 = d_2 \) or \( d_1 = -d_2 \). Thus, the axes must be parallel (or coincident) for the moment of inertia to be equal. ### Conclusion for Statement-1 Therefore, Statement-1 is **false** because the axes must be parallel for the moment of inertia to be equal, but it does not imply that they cannot be coincident. ### Step 4: Understanding Statement-2 **Statement-2:** "From the parallel axis theorem \( I = I_{cm} + md^2 \), where all terms have usual meaning." This statement is a direct application of the parallel axis theorem and is indeed true. The formula correctly describes how to calculate the moment of inertia about an axis that is parallel to the centroidal axis. ### Conclusion for Statement-2 Thus, Statement-2 is **true**. ### Final Answer - Statement 1 is false. - Statement 2 is true. The correct answer is option 4: Statement 1 is false, Statement 2 is true. ---

To analyze the given statements, we need to evaluate each one separately. ### Step 1: Understanding Statement-1 **Statement-1:** "If the moment of inertia of a rigid body is equal about two axes, then both the axes must be parallel." To understand this statement, we need to recall the definition of moment of inertia and how it varies with the choice of axes. The moment of inertia \( I \) of a rigid body depends on the axis about which it is calculated. If we have two different axes, the moment of inertia can be different unless certain conditions are met. ### Step 2: Applying the Parallel Axis Theorem ...
Promotional Banner

Topper's Solved these Questions

  • PART TEST 6

    RESONANCE ENGLISH|Exercise Exercise|30 Videos
  • SEMICONDUCTORS

    RESONANCE ENGLISH|Exercise Exercise|29 Videos

Similar Questions

Explore conceptually related problems

Assertion: Moment of inertia of a rigid body about any axis passing through its centre of mass is minimum Reason: From theorem of parallel axis I=I_(cm)+Mr^(2)

Moment of inertia I of a solid sphere about an axis parallel to a diameter and at a distance x from it varies as:

Moment of inertia of a ring of radius R about a diametric axis is 25 "kg m"^(2) . The MI of the ring about a parallel axis at a distance R from the centre is

Find the moment of inertia of the two uniform joint rods about point P as shown in Fig. Use parallel axis theorem. Mass of each rod is M .

The moment of inertia of cylinder of radius a, mass M and height h about an axis parallel to the axis of the cylinder and distance b from its centre is :

The moment of inertia of a solid sphere about an axis passing through the centre radius is 2/5MR^(2) , then its radius of gyration about a parallel axis t a distance 2R from first axis is

The moment of inertia of a circular loop of radius R, at a distance of R//2 around a rotating axis parallel to horizontal diameter of loop is

A wheel having moment of inertia 2 kg m^2 about its axis, rotates at 50 rpm about this axis. Find the torque that can stop the wheel in one minute.

Assertion:The moment of inertia of rigid body depends only on the mass of the body, its shape and size. Reason: Moment of inertia I = MR^2 where M is the mass of the body and R is the radius vector.

Calculate the moment of inertia of a ring of mass 2kg and radius 2cm about an axis passing through its centre and perpendicular to its surface.

RESONANCE ENGLISH-RIGID BODY DYNAMICS-Exercise
  1. S(1): Net torque on a system due to all internal force about any point...

    Text Solution

    |

  2. A rigid body is in pure rotation, that is, undergoing fixed axis rotat...

    Text Solution

    |

  3. A particle falls freely near the surface of the earth. Consider a fixe...

    Text Solution

    |

  4. A particle has a linear momentum p and position vector r. the angular ...

    Text Solution

    |

  5. In the given figure a ball strikes a uniform rod of same mass elastica...

    Text Solution

    |

  6. A disc of circumference s is at rest at a point A on horizontal surfac...

    Text Solution

    |

  7. A hole of radius R/2 is cut from a thin circular plate of raduis R as ...

    Text Solution

    |

  8. A uniform disc of mass m and radius R is rolling up a rough inclined p...

    Text Solution

    |

  9. A uniform cube of side a and mass m rests on a rough horizontal table....

    Text Solution

    |

  10. If radius of the earth contracts to half of its present value without ...

    Text Solution

    |

  11. A disc of mass M and radius R is suspended in a vertical plane by a ho...

    Text Solution

    |

  12. A particle performing uniform circular motion has angular momentum L. ...

    Text Solution

    |

  13. A small ball of radius r rolls down without sliding in a big hemispher...

    Text Solution

    |

  14. A solid iron sphere A rolls down an inclined plane, while another holl...

    Text Solution

    |

  15. A solid sphere and a solid cylinder having the same mass and radius, r...

    Text Solution

    |

  16. A ring, a disc a sphere and spherical shells are simutaneously release...

    Text Solution

    |

  17. Consider a wheel of a bicycle rolling on a level road at a linear spee...

    Text Solution

    |

  18. Statement 1: A solid sphere and a hollow sphere of same radius and sam...

    Text Solution

    |

  19. Statement-1: if moment of inertia of a rigid body is equal about two a...

    Text Solution

    |

  20. Statement-1 : A thin uniform rod is undergoing fixed axis rotation abo...

    Text Solution

    |