A hydrogen atom consists of a proton and an electron. If the orbital radius of the electron increases

The potential energy increases  if the orbital radius increases.

Explanation:

  The orbital radius of the electron increases means the distance from the nucleus of the hydrogen atom increase.

 The nucleus is positively charged .

The potential energy is given by  P.E = -

             where Z is the atomic number      

                           r is the radius

The negative sign indicates that the electron which is revolving is bound to nucleus.

As the radius and potential energy are inversely proportional it is clear that when radius increase the potential energy become less negative which means the potential energy increases when the orbital radius increase.