| Assertion (A): | A black body is an ideal body that emits and absorbs radiation of all frequencies. | 
| Reason (R): | The frequency of radiation emitted by a body goes from lower frequency to a higher frequency with an increase in 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. | (A) is False but (R) is True. | 
| Assertion (A): | The kinetic energy of photo-electrons increases with an increase in the frequency of incident light where v>v0. | 
| Reason (R): | Whenever the intensity of light is increased the number of photo-electron ejected always increases. | 
| 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. | (A) is False but (R) is True. |