Asked in ETEA MDCAT 2011 2011Moderate

If the temperature of the black body doubles, the intensity of radiation from it will become:

Correct answer: D. sixteen times

  • A. double
  • B. four times
  • C. six times
  • D. sixteen times

Explanation

BLACK BODY: A blackbody is a theoretical or model body that absorbs all radiation falling on it, reflecting or transmitting none. It is a hypothetical object that is a "perfect" absorber and "perfect" emitter of radiation over all wavelengths. Stefan-Boltzmann Law: It relates the total energy emitted (E) to the absolute temperature (T). E ∝ T⁴ We know that the intensity of the radiation from a black body is directly proportional to its energy. Thus, it can be concluded that if we increase the temperature of the black body by 2 (i.e., we double it), the intensity increases by 2⁴ i.e. it increases 16 times). Thus, option 'D' is the correct answer.

Last updated

About Quantum Theory and Radiation

Quantum theory treats electromagnetic radiation as packets of energy called photons, with energy proportional to frequency through E equals hf. The topic covers Planck's hypothesis, photon momentum, the photoelectric effect, threshold frequency, work function and wave particle duality, distinguishing quantised energy exchange from classical continuous radiation.

Practise Dawn of Modern Physics

739 free Dawn of Modern Physics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Physics questions like this

Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions