Class 12 Physics Chapter 11 - Dual Nature of Radiation and Matter MCQ and Assertion Questions

A proton and an alpha particle have equal momentum. The ratio of their kinetic energies \((E_p/E_a)\) and de Broglie wavelengths associated with them \((\lambda_p/\lambda_a)\) respectively are:

While studying photoelectric emission from a given surface, the wavelength of the incident radiation is changed from 600 nm to 400 nm, keeping the intensity of radiation the same. Then :

The kinetic energy of a charged particle is increased to four times of its initial value. The de Broglie wavelength associated with the particle will :

Assertion (A) : If accelerated electrons are passed through a narrow slit, a diffraction pattern is observed.

Reason (R) : Electrons behave as both particles and waves.

Radiation of wavelength 200 nm is incident on a photosensitive surface of work function 4·2 eV. The kinetic energy of fastest photoelectrons emitted from this surface will be close to :

The momentum of a photon associated with a microwave of wavelength 4·00 cm is :

Photons of frequency v are incident on the surfaces of two metals A and B of threshold frequencies \(\frac{v}{2}\) and \(\frac{v}{3}\) . The ratio of maximum kinetic energy of electrons emitted from metal A to that from metal B is :

A 500 nm photon is incident normally on a perfectly reflecting surface and is reflected. The value of momentum transferred to the surface is :

Assertion (A) : Photoelectric current depends upon the intensity of the incident radiation.

Reason (R) : Stopping potential is independent of the intensity of the incident radiation.