With the help of satellites and radars, a cyclone warning is issued _______ in advance. उपग्रहों तथा रेडारों की सहायता से, चक्रवात की चेतावनी को _______ पहले जारी किया जाता है।
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [a0 is Bohr radius]: