Assertion (A): | At room temperature water does not sublimate from ice to steam. |
Reason (R): | The critical point of water is much above room temperature. |
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. |
Assertion (A): | Water kept in an open vessel will quickly evaporate on the surface of the moon. |
Reason (R): | The temperature at the surface of the moon is much higher than the boiling point of water. |
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. |
Assertion (A): | If you decrease or increase the temperature of the water below or above 4°C respectively, its volume increases. |
Reason (R): | Density of water is maximum at 4°C. |
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. |
Assertion (A): | The emissive power of a body at a temperature T (in K) is directly proportional to T4. |
Reason (R): | Good emissive power of a body means the body is a good radiator. |
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. |
Assertion (A): | Material used for making cooking utensils is the one having high specific heat and high conductivity. |
Reason (R): | Low conductivity means high specific heat. |
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. |
Assertion (A): | Evaporation occurs at any temperature whereas the boiling point depends on the external pressure. |
Reason (R): | Evaporation of a liquid occurs from the surface of a liquid at all temperatures whereas boiling takes place at a temperature determined by the external pressure. |
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. |
Assertion (A): | With rise in temperature, time period of a pendulum remains same. |
Reason (R): | Time period is not dependent on temperature. |
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. |
Assertion (A): | A body that is a good radiator is also a good absorber of radiation at a given wavelength. |
Reason (R): | According to Kirchhoff's law, the absorptivity of a body is equal to its emissivity at a given wavelength. |
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. |
Assertion (A): | In a pressure cooker the water is brought to a boil. The cooker is then removed from the stove. Now on removing the lid of the pressure cooker, the water starts boiling again. |
Reason (R): | The impurities in water bring down its boiling point. |
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. |