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): | 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. |