A particle is dropped from a height \(H.\) The de-Broglie wavelength of the particle as a function of height is proportional to:
1. \(H\)
2. \(H^{1/2}\)
3. \(H^{0}\)
4. \(H^{-1/2}\)

Subtopic:  De-broglie Wavelength |
 65%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The wavelength of a photon needed to remove a proton from a nucleus which is bound to the nucleus with \(1~\text{MeV}\) energy is nearly:
1. \(1.2~\text{nm}\)
2. \(1.2\times 10^{-3}~\text{nm}\)
3. \(1.2\times 10^{-6}~\text{nm}\)
4. \(1.2\times 10~\text{nm}\)

Subtopic:  Einstein's Photoelectric Equation |
 72%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Consider a beam of electrons (each electron with energy \(E_0)\) incident on a metal surface kept in an evacuated chamber. Then:

1. no electrons will be emitted as only photons can emit electrons.
2. electrons can be emitted but all with energy, \(E_0\).
3. electrons can be emitted with any energy, with a maximum of \(\mathrm{E}_0-\phi\) (\(\phi\) is the work function).
4. electrons can be emitted with any energy, with a maximum \(E_0\).
Subtopic:  Electron Emission |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

A particle moves in a closed orbit around the origin, due to a force which is directed towards the origin. The de-Broglie wavelength of the particle varies cyclically between two values \(\lambda_{1} ,   \lambda_{2}\) with \(\lambda_{1} > \lambda_{2}\). Which of the following statement/s is/are true?
(a) The particle could be moving in a circular orbit with origin as the centre.
(b) The particle could be moving in an elliptic orbit with origin as its focus.
(c) When the de-Broglie wavelength is \(λ_1\), the particle is nearer the origin than when its value is \(λ_2\).
(d) When the de-Broglie wavelength is \(λ_2\), the particle is nearer the origin than when its value is \(λ_1\).

 
Choose the correct option:
1. (b), (d)
2. (a), (c)
3. (b), (c), (d)
4. (a), (c), (d)

Subtopic:  De-broglie Wavelength |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Photons absorbed in matter are converted to heat. A source emitting \(n\) photon/sec of frequency \(\nu\) is used to convert \(1\) kg of ice at \(0^{\circ}\text{C}\) to water at \(0^{\circ}\text{C}\). Then, the time \(T\) taken for the conversion:
(a) decreases with increasing \(n\), with \(\nu\) fixed
(b) decreases with \(n\) fixed, \(\nu\) increasing
(c) remains constant with \(n\) and \(\nu\) changing such that \(n\nu=\) constant
(d) increases when the product \(n\nu\) increases

 
Choose the correct option:
1. (b), (d)
2. (a), (c), (d)
3. (a), (d)
4. (a), (b), (c)

Subtopic:  Particle Nature of Light |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The de-Broglie wavelength of a photon is twice the de-Broglie wavelength of an electron. The speed of the electron is \(v_e = \dfrac c {100}\). Then,

1. \(\dfrac{E_e}{E_p}=10^{-4}\)
2. \(\dfrac{E_e}{E_p}=10^{-2}\)
3. \(\dfrac{P_e}{m_ec}=10^{-2}\)
4. \(\dfrac{P_e}{m_ec}=10^{-4}\)

Subtopic:  De-broglie Wavelength |
 59%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

Two particles \(A_1\) and \(A_2\) of masses \({m_1},m_2~({m_1>m_2})\) have the same de-Broglie wavelength. Then:
(a) their momenta (magnitude) are the same.
(b) their energies are the same.
(c) energy of \(A_1\) is less than the energy of \(A_2\).
(d) energy of \(A_1\) is more than the energy of \(A_2\).
 
Choose the correct option:
1. (b), (c)
2. (a), (c)
3. (c), (d)
4. (b), (d)
Subtopic:  De-broglie Wavelength |
 75%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Relativistic corrections become necessary when the expression for the kinetic energy \(\dfrac{1}{2} mv^{2}\), becomes comparable with \(mc^{2}\), where \(m\) is the mass of the particle. At what de-Broglie wavelength, will relativistic corrections become important for an electron?
(a) \(\lambda = 10~\text{nm}\) (b) \(\lambda = 10^{-1}~\text{nm}\)
(c) \(\lambda = 10^{- 4}~\text{nm}\) (d) \(\lambda = 10^{- 6}~\text{nm}\)

Choose the correct option:
1. (a), (c)
2. (a), (d)
3. (c), (d)
4. (a), (b)

Subtopic:  De-broglie Wavelength |
 51%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

An electron (mass \(m\)) with an initial velocity \(\overset{\rightarrow}{v} = v_{0} \hat{i}\) is in an electric field \(\overset{\rightarrow}{E} = E_{0} \hat{j}\). If \(\lambda_{0} = \dfrac{h}{ {mv}_0}\), its de-Broglie wavelength at time \(t\) is given by:

1. \(\lambda_0\)

2. \(\lambda_{0} \sqrt{1 + \dfrac{e^{2} E_{0}^{2} t^{2}}{m^{2} v_{0}^{2}}}\)

3. \(\dfrac{\lambda_{0}}{\sqrt{1 + \dfrac{e^{2} E_{0}^{2} t^{2}}{m^{2} v_{0}^{2}}}}\)

4. \(\dfrac{\lambda_{0}}{\left(1 + \dfrac{e^{2} E_{0}^{2} t^{2}}{m^{2} v_{0}^{2}}\right)}\)

Subtopic:  De-broglie Wavelength |
 65%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

An electron (mass \(m\)) with an initial velocity \(\vec{v}={v}_0 \hat{i}\) \(({v}_0>0)\) is in an electric field \(\vec{E}=-{E}_0 \hat{i}\)(\(E_0\) = constant \(>0\)). Its de-Broglie wavelength at time \(t\) is given by:
1. \(\dfrac{\lambda_0}{\left(1+\dfrac{e E_0}{m} \dfrac{t}{{v}_0}\right)}\) 2. \(\lambda_0\left(1+\dfrac{e E_0 t}{m {v}_0}\right)\)
3. \(\lambda_0 \) 4. \(\lambda_0t\)
Subtopic:  De-broglie Wavelength |
 76%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch