A certain metallic surface is illuminated with monochromatic light of wavelength \(\lambda\). The stopping potential for photoelectric current for this light is \(3V_0\). If the same surface is illuminated with light of wavelength \(2\lambda\), the stopping potential is \(V_0\). The photoelectric effect's threshold wavelength for this surface is?
1. \(6\lambda\)
2. \(4\lambda\)
3. \(\dfrac{\lambda}{4}\)
4. \(\dfrac{\lambda}{6}\)

Subtopic:  Einstein's Photoelectric Equation |
 77%
From NCERT
NEET - 2015
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Which of the following figures represents the variation of the particle momentum and the associated de-Broglie wavelength?

1.   2.
3.
4.
Subtopic:  De-broglie Wavelength |
 85%
From NCERT
NEET - 2015
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A photoelectric surface is illuminated successively by monochromatic light of wavelengths \(\lambda\) and \(\frac{\lambda}{2}\). If the maximum kinetic energy of the emitted photoelectrons in the second case is \(3\) times that in the first case, the work function of the surface of the material will be:
(\(h\) = Planck’s constant, \(c\) = speed of light)
1. \(\frac{hc}{2\lambda}\)
2. \(\frac{hc}{\lambda}\)
3. \(\frac{2hc}{\lambda}\)
4. \(\frac{hc}{3\lambda}\)
Subtopic:  Einstein's Photoelectric Equation |
 71%
From NCERT
NEET - 2015
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

Light with a wavelength of \(500\) nm is incident on a metal with a work function of \(2.28\) eV. The de Broglie wavelength of the emitted electron will be:
1. \( <2.8 \times 10^{-10}~\text{m} \)
2. \( <2.8 \times 10^{-9}~\text{m} \)
3. \( \geq 2.8 \times 10^{-9}~\text{m} \)
4. \( <2.8 \times 10^{-12}~\text{m} \)

Subtopic:  De-broglie Wavelength |
 60%
From NCERT
NEET - 2015
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Light with an energy flux of \(25\times 10^{4}~\text{Wm}^{-2}\) falls on a perfectly reflecting surface at normal incidence. If the surface area is \(15~\text{cm}^2\), then the average force exerted on the surface is:
1. \(1.25\times 10^{-6}~\text{N}\)
2. \(2.5\times 10^{-6}~\text{N}\)
3. \(1.2\times 10^{-6}~\text{N}\)
4. \(3.0\times 10^{-6}~\text{N}\)

Subtopic:  Particle Nature of Light |
 62%
NEET - 2014
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

When the energy of the incident radiation is increased by \(20\%\), the kinetic energy of the photoelectrons emitted from a metal surface increases from \(0.5\) eV to \(0.8\) eV. The work function of the metal will be:
1. \(0.65\) eV
2. \(1.0\) eV
3. \(1.3\) eV
4. \(1.5\) eV
Subtopic:  Einstein's Photoelectric Equation |
 67%
From NCERT
NEET - 2014
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

What will be the percentage change in the de-Broglie wavelength of the particle if the kinetic energy of the particle is increased to \(16\) times its previous value?
1. \(25\)
2. \(75\)
3. \(60\)
4. \(50\)

Subtopic:  De-broglie Wavelength |
 69%
From NCERT
NEET - 2014
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The wavelength \(\lambda_{e}\) of an electron and \(\lambda_{p}\) of a photon of the same energy \(E\) are related as:
1. \(\lambda_p \propto \lambda^2_e\)
2. \(\lambda_p \propto \lambda_e\)
3. \(\lambda_p \propto \sqrt{\lambda_e}\)
4. \(\lambda_p \propto \frac{1}{\sqrt{\lambda_e}}\)

Subtopic:  De-broglie Wavelength |
 54%
From NCERT
NEET - 2013
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A 200W sodium street lamp emits yellow light of wavelength 0.6 μm. Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is 

(1) 1.5×1020                               

(2) 6×1018

(3) 62×1020                                 

(4) 3×1019

Subtopic:  Electron Emission |
 68%
From NCERT
NEET - 2012
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

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V.The threshold frequency of the material is:

(1)4×1015Hz                               

(2)5×1015Hz

(3)1.6×1015Hz                           

(4)2.5×1015Hz

Subtopic:  Einstein's Photoelectric Equation |
 64%
From NCERT
NEET - 2012
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