A circular disc A of radius \(r\) is made from an iron plate of thickness \(t\) and another circular disc B of radius \(4r\) is made from an iron plate of thickness \(t/4.\) The relation between the moments of inertia \(I_A\) and \(I_B\) is:
1. | \(I_A>I_B\) |
2. | \(I_A=I_B\) |
3. | \(I_A<I_B\) |
4. | \(t\) and \(r\) | depends on the actual values of
A closed cylindrical tube containing some water (not filling the entire tube) lies in a horizontal plane. If the tube is rotated about a perpendicular bisector, the moment of inertia of water about the axis:
1. | increases |
2. | decreases |
3. | remains constant |
4. | increases if the rotation is clockwise and decreases if it is anticlockwise |
The moment of inertia of a uniform semicircular wire of mass \(\mathrm{M}\) and radius \(\mathrm{r}\) about a line perpendicular to the plane of the wire through the centre is:
1. \(\mathrm{Mr}^{2}\)
2. \(\frac{1}{2} \mathrm{Mr}^{2}\)
3. \(\frac{1}{4} \mathrm{Mr}^{2}\)
4. \(\frac{2}{5} \mathrm{Mr}^{2}\)
Let \(I_1\) and \(I_2\) be the moments of inertia of two bodies of identical geometrical shape, the first made of aluminium and the second of iron:
1. | \(I_1 <I_2\) |
2. | \(I_1 = I_2\) |
3. | \(I_1>I_2\) |
4. | \(I_1\) and \(I_2\) depends on the actual shapes of the bodies | The relation between
A body having its centre of mass at the origin has three of its particles at (a, 0, 0), (0, a, 0), (0, 0, a). The moments of inertia of the body about the X and Y axes are 0.20 kg-m2 each. The moment of inertia about the Z-axis:
1. is 0.20 kg-m2
2. is 0.40 kg-m2
3. is \(0.20\sqrt2\) kg-m2
4. cannot be deduced with this information
Let IA and IB be moments of inertia of a body about two axes A and B respectively. The axis A passes through the centre of mass of the body but B does not.
1. IA < IB
2. If IA < IB, the axes are parallel
3. If the axes are parallel, IA < IB
4. If the axes are not parallel, IA ≥ IB