Case : Read the passage and answer the question(s).

Number of magnetic field lines crossing a surface is called the magnetic flux. An electric current can be induced in a coil by flux change produced by another coil in its vicinity or flux change produced by the same coil. The former is called the mutual induction and the latter is called the self-induction. An induction furnace works on this principle. 

How does the flux through the coil vary with current?

Directly proportional

The flux of the coil varies directly with the current provided that the geometry of the coil does not change.