If a toroid used bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?

Answer the following questions: If a toroid uses bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?

A copper ring is held horizontally and a bar magnetic is dropped through the ring with its length along the axis of the ring (shown in the figure) will the acceleration of the falling magnet be equal to , greater than or less than that due to gravity?

When a voltemeter is put across a part of the circuit, does it read slightly less or more than the original voltage drop across the part? Explain.

Out of two materials 'A' has relatiave permeability slightly greater than unity while 'B' has less than unity. Identify the nature of materials 'A' and 'B'. Will their relative susceptibilities be positive or negative?

A solenoid with an iron core and a bulb are connected to a d.c. source. How does the brightness of the bulb change, when the iron core is removed from the solenoid?

A bird is in a wire cage hanging from a spring balance.Is the reading indicated on the balance,when the bird is flying out in the cage greater than ,less than or the same as that when the bird is sitting in the cage ?Explain.

A circular coil of 16 turns and radius 10 cm carrying a current of 0.75 A rests with its plane normal to an external field of magnitude 5.0 xx 10^-2 T. The coil is free to turn about an axis in its plane perpendicular to the field direction. When the coil is turned slightly and released, it oscillates about its stable equilibrium with a frequency of 2.0 s^-1 . What is the moment of inertia of the coil about its axis of rotation?

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?