Dual Nature of Matter and Radiation (KVPY (Kishore Vaigyanik Protsahan Yojana) Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics): Questions 7 - 10 of 19

If the wavelength of photon emitted due to transition of electron from fourth orbit to second orbit in a hydrogen atom is λ, then the wavelength of photon emitted due to transition of electron from fifth orbit to third orbit will be –

A stream of photons having energy 5 eV each impinges on a Lithium surface. The work function of Lithium is 2.9 eV. The emerging photo-electrons are slowed down by copper plate placed 3 mm away. If the potential difference between two metal plates is 1 V, the maximum distance the electrons can move away from the Lithium surface before being turned back is –

A singly ionized helium atom in an excited state (n = 4) emits a photon of energy 2.6 eV. Given that the ground state energy of hydrogen atom is -13.6 eV, the energy and quantum number (n) of the resulting state are respectively,

A 160 watt infrared source is radiating light of wavelength 50000 Å uniformly in all directions. The photon flux at a distance of 1.8m is of the order of,