Electro- magnetism questions | form six Physics

1. What is meant by the term Ballistic galvanometer?
2. State two conditions to be fulfilled for a galvanometer to be used as a ballistic galvanometer.
3. Consider a small flat coil which has N turns of area A and whose plane is perpendicular to a magnetic field of flux density B. If the search coil is connected to the ballistic galvanometer and the total resitance of the circuit is R, use the laws of electromagnetic induction to show that the charge  delivered to the galvanometer does not depend on how long it takes to remove the search coil from the field.

Distinguish between diamagnetic, paramagnetic and ferromagnetic materials on the basis of relative permeability μ_f.

Give the meaning of magnetization I for a paramagnetic material and use Curie’s law to
show how it relates with the absolute temperature (T).

Why the material used for making the core of a transformer should have narrow hysteresis loop?

A specimen of iron is uniformly magnetized by the magnetizing field of 300Am​^-1​ . If the
magnetic flux density in the specimen is 0.4Wbm​^-2​ , find the relative permeability,
susceptibility and the permeability of the specimen.

Consider two parallel co-axial circular coils of equal radius R, and number of turns ​ N ​ , carrying equal currents ​ I in the same direction and separated by a distance ​ R . ​ Show that , ​ where ​ B is the field on the axis around the mid-point between the coils which is uniformly distributed over a distance that is small as compared to ​ R and μ​_o is the permeability of free space.

Identify four factors that affect the force experienced by a current-carrying conductor in a magnetic field.

Write the mathematical expression which define magnetic flux density and use it to deduce its S.I units.

Apply the mathematical expression which define magnetic flux density to develop the formula for the force on a conductor carrying current I if the conductor and the magnetic fields are not at right angles.

Distinguish the terms magnetically soft and magnetically hard materials.