JEE MAIN - Physics (2015 (Offline) - No. 1)
As an electron makes a transition from an excited state to the ground state of a hydrogen - like atom/ion :
kinetic energy decreases, potential energy increases but total energy remains same
kinetic energy and total energy decrease but potential energy increases
its kinetic energy increases but potential energy and total energy decrease
kinetic energy, potential energy and total energy decrease
Forklaring
$$U = - K{{z{e^2}} \over r};\,\,T.E = {k \over 2}{{ze^2} \over r}$$
$$K.E = {k \over 2}{{z{e^2}} \over r}.$$ Here $$r$$ decreases
$$K.E = {k \over 2}{{z{e^2}} \over r}.$$ Here $$r$$ decreases