If a current carrying solenoid is compressed to half its length, the energy stored in its magnetic field is doubled - Physics - Magnetism And Matter

Question

If a current carrying solenoid is compressed to half its length,
the energy stored in its magnetic field is doubled What is the
source of this additional energy?

Shobhit Mittal · Accepted Answer

E=LI22v=ωLIas the inductance becomes half the current becomes double to maintain the volatge 
hence  new energyE'=L/22I22=2E  hence energy becomes double 
Regards

If a current carrying solenoid is compressed to half its length, the energy stored in its magnetic field is doubled. What is the source of this additional energy?