AIIMS Physics Dual Nature Of Matter Radiation Class 12 Questions

A particle A of mass m and initial velocity v collides with a particle B of mass m/2 which is at rest. The collision is head on, and elastic. The ratio of de-Broglie wavelengths λA to λB after the collision is

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.

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.

A beam of light of wavelength $400\text{ nm}$ and power $1.55\text{ mW}$ is directed at the cathode of a photoelectric cell. If only 10% of the incident photons effectively produce photoelectrons, then find current due to these electrons.[Given: $hc = 1240\text{ eV-nm}$, $e = 1.6 \times 10^{-19}\text{ C}$]

Assertion (A) A particle of mass M at rest decay into two particles of masses m₁ and m₂, having non-zero velocities will have ratio of de-Broglie wavelengths unity. Reason (R) Here we cannot apply conservation of linear momentum.

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.

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