Hi, please could someone help explain how magnetic flux works in Faraday's law as I struggle with electromagnetism. From what I understand, if you have a loop of wire in a magnetic field then you get an induced current if the flux is both changing and perpendicular to the plane of the loop. What I don't understand is why they fix an imaginary surface to the loop. The area inside the loop is just empty space so how has that got anything to do with the induction process? The wire just needs to 'see' a changing magnetic flux so the area inside the loop seems to serve no role as far as I can see, what am I missing? Also, what area do you assign for the flux when the magnetic field is outside the loop? Thank you in advance for any help offered!