- 1(current)
Q. No.The temperature of a body falls from \(50^{\circ}\text{C}\) to \(40^{\circ}\text{C}\) in \(10\) minutes. If the temperature of the surroundings is \(20^{\circ}\text{C},\)hen the temperature of the body after another \(10\) minutes will be:
1. \(36.6^{\circ}\text{C}\)
2. \(33.3^{\circ}\text{C}\)
3. \(35^{\circ}\text{C}\)
4. \(30^{\circ}\text{C}\)
1. \(50\) s
2. \(52\) s
3. \(42\) s
4. \(48\) s
A block of metal is heated to a temperature much higher than the room temperature and allowed to cool in a room free from air currents. Which of the following curves correctly represents the rate of cooling?
| 1. |  |
2. |  |
| 3. |  |
4. |  |
A certain quantity of water cools from \(70^{\circ}\mathrm{C}\) to \(60^{\circ}\mathrm{C}\) in the first 5 minutes and to \(54^{\circ}\mathrm{C}\) in the next 5 minutes.
The temperature of the surroundings will be:
| 1. | \(45^{\circ}\mathrm{C}\) | 2. | \(20^{\circ}\mathrm{C}\) |
| 3. | \(42^{\circ}\mathrm{C}\) | 4. | \(10^{\circ}\mathrm{C}\) |
Hot coffee in a mug cools from \(90^{\circ}\text{C}\) to \(70^{\circ}\text{C}\) in \(4.8\) minutes. The room temperature is \(20^{\circ}\text{C}.\) Applying Newton's law of cooling, the time needed to cool it further by \(10^{\circ}\text{C}\) should be nearly:
| 1. | \(4.2\) minute | 2. | \(3.8\) minute |
| 3. | \(3.2\) minute | 4. | \(2.4\) minute |
- 1(current)
Q. No.
© 2025 GoodEd Technologies Pvt. Ltd.