| Assertion (A): | If polar ice melts, days will be longer. |
| Reason (R): | Moment of inertia increases and thus angular velocity decreases. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
| 1. | \(3\) m/s2 | 2. | \(2\) m/s2 |
| 3. | zero | 4. | \(1\) m/s2 |
| 1. | \(12\) | 2. | \(14\) |
| 3. | \(16\) | 4. | \(18\) |

| 1. | \(\dfrac23\) m/s2 initially, but it varies with time. |
| 2. | \(\dfrac23\) m/s2 and is constant. |
| 3. | zero initially, but it reaches a maximum of \(1\) m/s2. |
| 4. | \(1\) m/s2 initially, but it decreases thereafter with time. |


A string is wrapped along the rim of a wheel of the moment of inertia \(0.10~\text{kg-m}^2\) and radius \(10~\text{cm}.\) If the string is now pulled by a force of \(10~\text N,\) then the wheel starts to rotate about its axis from rest. The angular velocity of the wheel after \(2~\text s\) will be:
| 1. | \(40~\text{rad/s}\) | 2. | \(80~\text{rad/s}\) |
| 3. | \(10~\text{rad/s}\) | 4. | \(20~\text{rad/s}\) |