The ground state energy of the hydrogen atom is \( -13.6\ \mathrm{eV} \). The kinetic energy and potential energy of the electron in this state, respectively, are:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 13.6\ \mathrm{eV},\ -27.2\ \mathrm{eV} \)
For an electron in a Bohr orbit, the kinetic energy is half the size of the potential energy, and the total energy is negative: \( K = -E \) and \( U = 2E \).
\( E = -13.6\,\mathrm{eV} \)
\( K = -E = 13.6\,\mathrm{eV} \)
\( U = 2E = -27.2\,\mathrm{eV} \)
Check: \( K+U = 13.6\,\mathrm{eV}-27.2\,\mathrm{eV} = -13.6\,\mathrm{eV} \). The kinetic energy is always positive and the potential energy is negative, because the electron is bound.
Note: This question is from NCERT (2026-27). NTA sets numerical questions from NCERT too, so do not ignore NCERT while practising numericals.
NCERT (2026-27):
Exercises – …
