Question

A solenoid with 19 turns/cm carries a current of 1.3 A.

(a) By how much does the magnetic field inside the solenoid increase when a close-fitting chromium rod is inserted? (See Table 35-2) T

(b) Find the magnetization of the rod. (See Table 35-2) A/m

Answer 1

a )

the initial magnetic field = _o n i

= 4 X 3.14 X 10^-7 X 19 X 100 X 1.3

= 3.102 X 10^-3 T

and the final magnetic field = _or n i

= ( 1 + _m ) o n i

= ( 1 + 2.7 X 10^-4 ) ( 4 X 3.14 X 10^-7 X 19 X 100 X 1.3

= 3.103 X 10^-3 T

then dB = 3.103 X 10^-3 T - 3.102 X 10^-3 T

dB = 10^-6 T

dB = 1 T

the magnetic field inside the solenoid increase when

a close-fitting chromium rod is inserted is dB = 1 T

b )

the magnetization

M = _m n i

M = 2.7 X 10^-4 X 1900 X 1.3

so the magnetization of the rod is M = 0.6669 A/m

( i consider the values for Chromium

because the Table 35-2 is not availabe for me )