56) If threshold wavelength for tungsten is 2300?A⁰, then energy of the electrons emitted by UV light of wavelength 1800?A⁰?is

57) If maximum velocity with which an electron can be emitted from a photo cell is 3.75?10⁸cms^?1, then stopping potential is

58) Wavelength of light incident on a photo cell is 3000?A⁰, if stopping potential is 2.5 volts, then work function of the cathode of photo cell is

59) If the frequency of incident light on a certain metal is 8.2??10¹⁴Hz having threshold frequency of 3.3??10¹⁴?Hz , then cut off potential is

60) If light of frequency?10¹⁵?Hz is incident on sodium having work function 2.5eV,then energy of emitted photoelectrons is