Physics MCQs for NEET — Practice Questions with Answers

The context explicitly states: 'From Chapter 11, we have $\lambda = h/p$, where $p$ is the magnitude of the electron’s momentum.' and also in the 'DUAL_NATURE_OF_RADIATION_AND_MATTER' chapter: 'The de Broglie wavelength ($\lambda$) associated with a moving particle is related to its momentum $p$ as: $\lambda = h/p$.'

The text states: 'Thus de Broglie hypothesis provided an explanation for Bohr’s second postulate for the quantisation of angular momentum of the orbiting electron.'

The text says: 'The quantised electron orbits and energy states are due to the wave nature of the electron and only resonant standing waves can persist.'

The context mentions the condition for stable orbits: '$2\pi r_n = n\lambda$, n = 1, 2, 3...'

The context from 'DUAL_NATURE_OF_RADIATION_AND_MATTER' states: 'This wavelength is so small that it is beyond any measurement. This is the reason why macroscopic objects in our daily life do not show wave-like properties. On the other hand, in the sub-atomic domain, the wave character of particles is significant and measurable.'

The text explicitly states: 'The French physicist Louis de Broglie explained this puzzle in 1923, ten years after Bohr proposed his model.'

The text shows the derivation: From Eq. (12.12), which is $2\pi r_n = n\lambda$, and substituting $\lambda = h/mv_n$, we get $2\pi r_n = n(h/mv_n)$, which rearranges to $m v_n r_n = nh/2\pi$. This shows the combination of de Broglie's wavelength and the standing wave condition leads to Bohr's quantization condition.

The text states: 'Of all the postulates, Bohr made in his model of the atom, perhaps the most puzzling is his second postulate. It states that the angular momentum of the electron orbiting around the nucleus is quantised'.

The context ('DUAL_NATURE_OF_RADIATION_AND_MATTER' summary) mentions: 'The dualism of matter is inherent in the de Broglie relation which contains a wave concept ($\lambda$) and a particle concept ($p$).'

The text from 'DUAL_NATURE_OF_RADIATION_AND_MATTER' states: 'It is significantly measurable (of the order of the atomic-planes spacing in crystals) only in case of sub-atomic particles like electrons, protons, etc. (due to smallness of their masses and hence, momenta).'