Why Does an Inductor Store Energy After No Current?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
1 reply · 2K views
fight_club_alum
Messages
63
Reaction score
1
Screen Shot 2019-11-05 at 5.45.47 AM.jpg

I calculated all the required in this problem correctly but can't understand why the sum of energy extracted and absorbed is not zero.
They are:
>0: 0J
0 <=E<=25: 4t^2 J
25 <= E <= 50: 4t^2 - 0.4t + 10 * 10^-3t J
E > 50: 0 J

Does that mean that an inductor stores energy even after there is no current?
Thanks

[Moderator's note: Moved from a technical forum and thus no template.]
 
Last edited by a moderator:
Physics news on Phys.org
fight_club_alum said:
25 <= E <= 50: 4t^2 - 0.4t + 10 * 10^-3t J
Check your working.

The energy stored in an inductor depends only on the present instantaneous value of its current. So when current = 0, no energy is stored.
 
  • Like
Likes   Reactions: fight_club_alum