Planck's quantum theory proposed that energy is emitted or absorbed
Correct answer: B. in discrete packets called quanta, each of energy hf
- A. continuously in any amount
- B. in discrete packets called quanta, each of energy hf
- C. only as heat
- D. only by solids
Explanation
Planck found that black body radiation could only be explained if the energy came in multiples of hf, where h is Planck's constant and f the frequency. Classical physics assumed a continuous exchange and predicted infinite energy at short wavelengths, the so called ultraviolet catastrophe. Quantisation resolved that failure and began quantum physics.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
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.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.