Hi.
If you pass alternating current in a wire inside this first coil at left, what is the expected reading at the coil terminals ?


If you pass alternating current with a wire inside this second coil at right, what is the expected reading at the coil terminals ?

 

in first case zero, in second case some voltage

 

If you pass alternating current in a wire inside this first coil at left

Define "inside".

 

Voltage expected.
U=I*2*pi*f*L
The formula is valid if the current is sinusoidal and coil resistance is small

 

Identify 'coil terminals' is the implication that both are double coils?
(inner & outer?)

 

Hello,

Read the article on current transformers:
https://en.wikipedia.org/wiki/Current_transformer

In there you will find this picture:

Bertus