Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Moment of inertia of a circular disc of mass M and radius R about X , Y axes (passing through its plane) and Z-axis which is perpendicular to its plane were found to be I x , I y and…

Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Moment of inertia of a circular disc of mass $M$ and radius $R$ about $X, Y$ axes (passing through its plane) and Z-axis which is perpendicular to its plane were found to be $I_{x}, I_{y}$ and $I_{z}$ , respectively. The respective radii of gyration about all the three axes will be the same.

Reason R: A rigid body making rotational motion has fixed mass and shape. In the light of the above statements, choose the most appropriate answer from the options given below:

Aicharya · Accepted Answer

I z = I x + I y (using perpendicular axis theorem) and I = m k 2 ( K : radius of gyration) so m K z 2 = m K x 2 + m K y 2 K z 2 = K x 2 + K y 2 So radius of gyration about axes x , y and z will not be same, hence assertion A is not correct reason R is correct statement (property of a rigid body).

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.…

Solution