explain the answer for this

 

its answer is zero ... explain why

 

Aye Aye Sir.

 

You should have posted this in the Homework Help forum.

 

Didja tell the mods? (I told them. That's what the red outlined triangle is for. Do not duplicate my notice to the Mods.)

 

Hello,

The thread is moved to the Homework Help section.
Now you are here, please read the following:
PLEASE READ - Posting Questions in the Homework Help Forum

Bertus

 

Show how you approach the problem. Nobody is going to do your homework for you.

 

Here is a hint: Look for information about "air gap" transformer cores, and why they are used.