Select an alternative from of uncertainly principle from the following_______________?
Correct answer: B. ∆E . ∆t = h
- A. ∆E = h/m∆c(1-cosθ)
- B. ∆E . ∆t = h
- C. mc2 = hv
- D. Any of above
Explanation
The energy-time form of the uncertainty principle is ΔE Δt approximately equal to h/4π, or often written approximately as h in simplified statements. It expresses that a short-lived state has an uncertain energy. Students may choose c because it is Einstein's mass-energy relation, but that equation is not an uncertainty relation.
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
0.001 kg mass will be equivalent to_________________?
A black body emitting all the radiation in the visible region appears________.
A black body has the property to _____________ all the radiation entering it.
A black body is one that
A blacksmith is heating an iron axe on a high degree burner. While heating the axe, he noted that different colours are produced. Which of the following colours shows the highest temperature of the iron axe?