Assume that each iron atom has a permanent magnetic moment equal to 2 Bohr magneton . The number density of atoms in iron is `8.52 xx 10^28 m^-3`. Find the maximum value of intensity of magnetisation.

Assume that each iron atom has a permanent magnetic moment equal to 2 Bohr magneton . The number density of atoms in iron is 8.52 xx 10^28 m^-3 . Find the maximum value of magnetic induction in an iron bar.

A magnet weighs 75 g and its magnetic moment is 2xx10^-4 A m^2 . If the density of the material of the magnet is 7.5 xx 10^3 kg m^-3 , calculate the intensity of magnetisation.

A current of 1.8 A flows through a wire of cross-sectional area 0.5 mm^(2) ? Find the current density in the wire. If the number density of conduction electrons in the wire is 8.8 xx 10^(28) m^(-3) , find the drift speed of electrons.

A paramagnetic gas consists of atoms each with a dipole moment of 1.5 xx 10^-23 j T^-1 . The temperature of the gas is 27^@C and its number density is 2xx10^26 m^-3 . What is the maximum magnetisation of the sample possible, when it is placed in an external magnetic field?

What is the electric potential at the surface of an iron nucleus? The radius of the nucelus is 4.2 xx 10^-15 m and the atomic number is 26.

A current of 10A is maintained in a conductor of cross-section 10^-4m^2 . If the number density of free electrons be 9 xx 10^28 m^-3 , calcualte the drift velocity of free electrons. Given, charge on electron, e = 1.6 xx 10^-19C

Estimate the average mass density of a sodium atom assuming its size to be about 2.5 overset@A . (Use the known values of Avogadro’s number and the atomic mass of sodium). Compare it with the density of sodium in its crystalline phase : 970 kg m^-3 . Are the two densities of the same order of magnitude ? If so, why ?

A rheostat has 100 turns of a wire of radius 0.4 mm having resistivity 4.2 xx 10^-7Omega m. The diameter of each turn is 3 cm. What is the maximum value of resistance it can introduce?