Question

A current-carrying solenoid of 50 turns/cm carries a current of 2 A. 

a. Find the magnetic intensity H at the center of the solenoid. 

b. A material P of magnetic susceptibility \(\chi_p\) = 5 x 10^-3 is introduced as the core of the solenoid. 

Is the material P diamagnetic, paramagnetic or ferromagnetic? Find the magnetization M developed in the core. 

c. The material P is now replaced by the material Q of magnetic susceptibility \(\chi _q\) = 5 x 10³ . Is the material Q diamagnetic, paramagnetic or ferromagnetic?  

d. Mention the type of magnetic material that has 

(i) M >> H 

(ii) M << H

Answer 1

a. Magnetic intensity, H = n I = 50 x 100 x 2 = 10⁴ A/m 

b. Since \(\chi _p\) = 5 x 10^-3 is small and positive, the material P is paramagnetic. 

Magnetization M developed in P, 

M = \(\chi _pH\) = 5 x 10^-3 x 10⁴ = 50 A/m 

c. Since \(\chi _q \)= 5 x 10³ is large and positive, the material Q is ferromagnetic. 

d. (i) Ferromagnetic material has magnetization M >> H 

(ii) Paramagnetic material has magnetization M << H.