This was in my test paper today:
A transformer is cut into half so that one half contains the primary coil and the other half contains the secondary coil. They are moved 30cm apart. Explain why the transformer would not work
The Attempt at a Solution
My answer: The magnetic field strength will be very weak so it would induce negligible emf in the coil.
Then my teacher gave me zero marks and said this is wrong.
His answer: The field lines will not reach the secondary coil. Therefore,not magnetic field lines are cut and emf is not induced.
I thought what the $%^&?
I think what he said is wrong. The magnetic field lines will reach any distance.
How is my answer wrong?