Magnetism and Electromagnetism
Materials subjected to rapid reversal of magnetism should have

High co-ercivity and low density
Large area of B-H loop
High permeability and low hysteresis loss
High co-ercivity and high retentivity

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Magnetism and Electromagnetism
A certain amount of current flows through a ring shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil?

Remains same
First increases and then decreases depending on the depth of iron in¬sertion
Decreases
Increases

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