An iron-cored solenoid has self inductance 2.8 H. When the core is removed, the self inductance become 2mH. What is the relative permeability of the core used?

If the self-inductance of an iron ore inductor increases from 0.01 m H to 10mH on introducing the iron core into it, what is the relative permeability of the core used?

The core of toroid having 3,000 turns has inner and outer radii of 11 cm and 12 cm respectively. The magnetic field in the core for a current of 0.70 A is 2.5 T. What is the relative permeability of the core?

How does the self inductance of an air coil change, when an iron rod is introduced in the coil?

A coil of wire of certain radius has 600 turns and a self inductance of 108 mH. What will be the self inductance of a similar coil, which has 500 turns?

A coil has an inductance of 1.5 xx 10^-2 H. Calculate the e.m.f. induced, when current in the coil changes at the rate 200 ampere per second.

A Rowland ring has 10^3 turns per uit length. On passing a current of 2 A, magnetic induction is measured to be 1.5 Wb m^-2 . Calculate relative permeability of the core.

Current changes from 12A to 7A in 2 seconds in a coil of self inductance 2H. Find the induced emf in the coil.

In a coil of self-induction 5 H, the rate of change of current is 2 A s^-1 . Then, e.m.f. induced in the coil is