In Young's double slit experiment, the distance between the slits and the screen is $$1.2 \mathrm{~m}$$ and the distance between the two slits is $$2.4 \mathrm{~mm}$$. If a thin transparent mica sheet of thickness $$1 \mu \mathrm{m}$$ and RI 1.5 is introduced between one of the interfering beams, the shift in the position of central bright fringe is
The de-Broglie wavelength associated with electron of hydrogen atom in this ground state is
The following graph represents the variation of photocurrent with anode potential for a metal surface. Here $$I_1, I_2$$ and $$I_3$$ represents intensities and $$\gamma_1, \gamma_2, \gamma_3$$ represent frequency for curves $$1,2$$ and $$3$$ respectively, then
The period of revolution of an electron revolving in nth orbit of $$\mathrm{H}$$-atom is proportional to