661 The characteristic X-rays spectrum is due to_____________? Physics Medium Full question → A The illumination of the target metal by ultra-violet radiation B The bombardment of the target by protons C The bombardment of target by electrons D The absorption of radiation by the target metal
662 The minimum wavelength of X-rays can further be reduced by _______________? Physics Medium Full question → A Reducing the pressure or cooling the target B Increasing the temperature of the filament. C Using a target element of higher atomic number D Increasing the potential difference between the cathode and the target
663 Radiation produced from TV picture tube is_____________? Physics Medium Full question → A B-rays B X-rays C Far infrared D Infrared
664 In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is_______________? Physics Medium Full question → A he/ev B he/Vc C eV/h D impossible to predict
665 Quality of X-rays depends upon ____________ A-filament current B-accelerating voltage C-material of the target ? Physics Medium Full question → A A & B B B & C C A & C D A B & C
666 When X-rays are passed through successive aluminum sheets what happens to their thickness ? Physics Medium Full question → A increases B it decreases C it remains same D sometimes increases and sometimes decreases
667 X-rays are similar in nature to_______________? Physics Medium Full question → A Cathode rays B Positive rays C γ-rays D Beta rays
668 In an electronic transition atom cannot emit______________? Physics Medium Full question → A γ-rays B Infra red radiation C Visible light D Ultraviolet rays
669 Radiation with wavelength longer than red lights______________? Physics Medium Full question → A ultraviolet rays B X-rays C infra red radiation D visible radiation
670 Reverse process of photoelectric effect is_______________? Physics Medium Full question → A pair production B Compton effect C annihilation of matter D X-rays production
671 The penetrating power of X-rays depends on their______________? Physics Medium Full question → A applied voltage B frequency C source D all of the above
672 Bracket series is obtained when all transition of electron terminate on_______________? Physics Medium Full question → A 4th orbit B 5th orbit C 3rd orbit D 2nd orbit
673 The electric P.E of an electron in an orbit at a distance rn from the positive charge_____________? Physics Medium Full question → A Ke2/rn B Ke2/rn2 C ÀKe2/rn D ÀKe2/rn2
674 Ground state energy of the 4th orbit in a H-atom is_____________? Physics Medium Full question → A 13.60 eV B 3.40 eV C 0.85 eV D 1.51 eV
675 Which one of following postulate is in accordance with the Rutherfords model ? Physics Medium Full question → A continuous spectra for atoms B discrete spectra for atoms C either continuous nor discrete D no spectrum
676 When we excite some atoms by heat collision or electrical discharge they will________________? Physics Medium Full question → A radiate electromagnetic energy with a continuous distribution of wavelength B absorb particular wavelengths when white light is incident on them C radiate electromagnetic energy of discrete characteristic wavelength D emit either invisible or visible light
677 In obtaining an X-ray photograph of our hand we use the principle of______________? Physics Medium Full question → A photo electric effect B ionization C shadow photograph D any of above
678 Photon of highest frequency will be absorbed when transition takes place from_____________? Physics Medium Full question → A 1st to 5th orbit B 2nd to 5th orbit C 3rd to 5th orbit D 4th to 5th orbit
679 The radiations emitted form hydrogen filled discharge tube show____________? Physics Medium Full question → A band spectrum B line spectrum C continuous spectrum D absorption spectrum
680 Total number of series in hydrogen spectrum is_____________? Physics Medium Full question → A three B four C five D six