AIIMS Physics Dual Nature Of Matter Radiation Class 12 Questions

Sodium and copper have work function 2.3 eV and 4.5 eV respectively. Then ratio of their threshold wavelength is nearest to

When a metallic surface is illuminated by a light of wavelength λ, the stopping potential for the photoelectric current is 3 V. When the same surface is illuminated by light of wavelength 2λ, the stopping potential is 1 V. The threshold wavelength for this surface is

Assertion: Photoelectric effect demonstrates the wave nature of light. Reason: The number of photoelectrons is proportional to the frequency of light.

In a photoelectric effect experiment, for radiation with frequency $\nu_0$ with $h\nu_0 = 8\text{ eV}$, electrons are emitted with energy $2\text{ eV}$. What is the energy of the electrons emitted for incoming radiation of frequency $1.25\nu_0$?

A particle of mass $m$ is projected from ground with velocity $u$ making angle $\theta$ with the vertical. The de Broglie wavelength of the particle at the highest point is:

A and B are two metals with threshold frequencies 1.8×10^14 Hz and 2.2×10^14 Hz. The two identical photons of energy 0.825 eV

For a given photosensitive material and frequency (> threshold frequency) of incident radiation, the photoelectric current varies with the intensity of incident light as

Assertion: Threshold frequency depends on material of metal used. Reason: Threshold wavelength $\propto$ Threshold frequency

Photoelectric effect experiments are performed using three different metal plates p, q and r having work functions $Q_p = 2.0\text{ eV}$, $Q_q = 2.5\text{ eV}$ and $Q_r = 3.0\text{ eV}$ respectively. A light beam containing wavelengths of $550\text{ nm}$, $450\text{ nm}$ and $350\text{ nm}$ with equal intensities illuminates each of the plates. The correct I-V graph of the experiment is (take $hc = 1240\text{ eV}\cdot\text{nm}$)

Assertion: Photoelectric effect can take place only with an electron bound in the atom. Reason: Electron is a fermion whereas proton is a boson.

In the following questions, a statement of assertion is given followed by a corresponding statement of reason. Assertion: The phenomenon of X⁻ray production is basically inverse of photoelectric effect. Reason: X⁻rays are electromagnetic waves.

Assertion: When certain wavelength of light fall on metal surface it ejects electron. Reason: Light was wave nature.

Assertion In photoelectron emission the velocity of electron ejected from near the surface is larger than that coming from interior of metal. Reason The velocity of ejected electron will be zero.

If velocity of a particle is three times that of electron and ratio of de Broglie wavelength of particle to that of electron is 1.814 × 10⁻⁴. The particle will be

Ratio of longest wavelengths corresponding to Lyman and Balmer series in hydrogen spectrum is

A photon is incident having frequency 1 × 10¹⁴ sec⁻¹. Threshold frequency of metal is 5 × 10¹³ sec⁻¹. Find the kinetic energy of the ejected electron.

If we assume kinetic energy of a proton is equal to energy of the photon, the ratio of de Broglie wavelength of proton to photon is proportional to

Whenever a stream of electrons collides with a stream of photons, in this collision, which of the following is not conserved?

If K₁ and K₂ are maximum kinetic energies of photoelectrons emitted when lights of wavelengths λ₁ and λ₂ respectively incident on a metallic surface. If λ₁ = 3λ₂, then

Assertion : A photon has no rest mass, yet it carries definite momentum. Reason : Momentum of photon is due to its energy and hence its equivalent mass.

Which of the following is matched wrongly?

Assertion: Stopping potential depends upon the frequency of incident light but is independent of the intensity of the light. Reason: The maximum kinetic energy of the photoelectrons is proportional to stopping potential.

What is the energy of photon whose wavelength is 6840 Å?

Hard X⁻rays for the study of fractures in bones should have a minimum wavelength of \( 10^{-11} \) m. The accelerating voltage for electrons in X⁻ray machine should be

In photoelectric effect, the electrons are ejected from metals if the incident light has a certain minimum

If alpha, beta and gamma rays carry same momentum, which has the longest wavelength

Assertion : The photoelectrons produced by a monochromatic light beam incident on a metal surface, have a spread in their kinetic energies. Reason : The work function of the metal varies as a function of depth from the surface.

Assertion : The energy (E) and momentum (p) of a photon are related by p = E/c. Reason : The photon behaves like a particle.

A photon of energy 4 eV is incident on a metal surface whose work function is 2 eV. The minimum reverse potential to be applied for stopping the emission of electrons is

We wish to see inside an atom. Assuming the atom to have a diameter of 100 pm, this means that one must be able to resolve a width of say 10 pm. If an electron microscope is used, the minimum electron energy required is about

Assertion : Photoelectric effect demonstrates the wave nature of light. Reason : The number of photoelectrons is proportional to the frequency of light.

A proton is about 1840 times heavier than an electron. When it is accelerated by a potential difference of 1 kV, its kinetic energy will be

Characteristic X⁻rays are produced due to

Mass of the proton is 1840 times that of electron. It is accelerated through a potential difference of 1 V. Find its kinetic energy.

The work function of a metal is 3.4 eV. If the frequency of incident radiation is increased to twice, then the work function of the metal becomes

Assertion (A) : On increasing the frequency of light larger number of photoelectrons are emitted. Reason (R) : The number of electrons emitted depends on the intensity of incident light.

Particle nature and wave nature of electromagnetic waves and electrons can be shown by