Assertion (A): The black body is an ideal body that emits and absorbs radiations of all frequencies. Reason (R): The frequency of radiation emitted by a body goes from a lower frequency to higher frequency with an increase in temperature.
Assertion (A): The black body is an ideal body that emits and absorbs radiations of all frequencies. Reason (R): The frequency of radiation emitted by a body goes from a lower frequency to higher frequency with an increase in temperature.

(i) Both A and R are true and R is the correct explanation of A.

(ii) Both A and R are true but R is not the explanation of A.

(iii) A is true and R is false.

(iv) Both A and R are false.

Correct Answer: (ii) Both A and R are true but R is not the explanation of A

Explanation: Body that emits and absorbs the radiation having all type of the frequencies is called the black body and the radiation emitted by these bodies are called the black body radiation.

The direct distribution of frequency from the dark body depends only on its temperature. At a given temperature, the radiation intensity increases with a decrease in the wavelength of the radiation and reaches a higher value than a given wavelength and begins to decrease with a continuous decrease in wavelengths.