Dual Nature of ...

Photons with energy 5eV are incident on a cathode C, on a photoelectric cell. The maximum energy of the emitted photoelectrons is 2eV. When photons of energy 6eV are incident on C, no photoelectrons will reach the anode A if the stopping potential of A relative to C is

By increasing the intensity of incident light keeping frequency (v >v₀ ) fixed on the surface of metal

In a photoelectric experiment, electrons are ejected from metals X and Y by light of intensity I and frequency f. The potential difference V required to stop the electrons is measured for various frequencies. If Y has a greater work function than X ; which one of the following graphs best illustrates the expected results ?

A image of the sun of formed by a lens of focal-length of 30 cm on the metal surface of a photo-electric cell and a photo-electrci current is produced. The lens forming the image is then replaced by another of the same diameter but of focal length 15 cm. The photo-electric current in this case is

A proton and an electron are accelerated by same potential difference have de-Broglie wavelength l_p and l_e .

An electron with initial kinetic energy of 100eV is acceleration through a potential difference of 50V. Now the de-Broglie wavelength of electron becomes.

If h is Planck 's constant is SI system, the momentum of a photon of wavelength 0.01 Åis

The angular momentum of an electron in the hydrogen atom is . Here h is Planck 's constant. The kinetic energy of this electron is

Consider the following electronic energy level diagram of H-atom : Photons associated with shortest and longest wavelengths would be emitted from the atom by the transitions labelled.

If the electron in a hydrogen atom were in the energy level with n = 3, how much energy in joule would be required to ionise the atom ? (Ionisation energy of H-atom is 2.18 ×10^-18 J)