Fill in the blank spaces:
The self inductance of a doubly wound coil is _______.

Self induction of a coil varies

Fill in the blank spaces: Mutual inductances between two coils is maximum when the coils are ___________.

Fill in the blank spaces: An ideal inductor is a coil of_______ resistance.

Fill in the blank spaces: Emf is induced in a closed coil only when the magnetic flux linked with the coil ___________ with respect to time.