question_answer 135)

  Assertion (A): 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.

Answer:

  (b) Black bodies can absorb and emit the radiations of all frequencies. On increasing the temperature of black body, the energy and frequency of the emitted radiation increases.