Photo electronic emission is observed from a surface for frequencies g&h (g>h) . If kinetic energy of photo electron in two cases are in ratio l:k then threshold frequncy is?
Calaculate the number of photns of wave lentgh 253.7 nm emitted per sec at 1000K by a 200W MERCURY LAMP
Size of microscopic particle is 1 micron & mass is 6*10^ -13 g . If its position may be measured upto 0.1% of its size the uncertainity in velocity in cm^-1 is ?
When an electron with charge " e " & mass ' m ' moves with velocity ' v ' around the nucleus having nuclear chage ' Z ' in acircular orbit of radius ' r ' the potential energy of electon will be
The min. & max. values of wave length in Lymann series of H-atom are
A cricket ball of mass 0.5 kg is moving with a velocity of 100m/s the de - Broglie wave lengthof particle is
The energy of Bohr ' s first orbit of Hydrogen atomis is -13.6 eV/atom . The energy of Bohr ' s eighth orbit of Helium atom is
The mass of Gold atom is 197 & density is 19.7g / cc . Radius of Gold is approximately
The first emission line of hydrogen atomic spectrum in Balmer series appears at (R=constant)
The de Broglie wave length of a bullet of mass 2 gm moving with velocity of 2m/s is