The ionization potential of hydrogen atom is 13.6eV. The energy required to remove an electron from the second orbit of hydrogen will be?

Ionisation energy of hydrogen atom is equal to the magnitude of energy of its first orbit i.e. E1 = 13.6eV
Magnitude of energy of 2nd orbit, E2 = 13.6/2² = 3.4eV
Thus energy required to remove an electron from second orbit is equal to 3.4eV.