The rotational inertia of your leg is greater when your leg is
straight
bent
same either way

Inertia doesn't apply to living flesh, only dead matter. Having said that, sure hope you're not a zombie.  

So I'm not misunderstood, living flesh always has force applied, whether in rotation or anti rotation. There is no complete relaxation, therefore no inertia. So, the answer is Same either way.

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j