Question

A solenoid has core of a material with relative permeability 500 and its windings carry a current of 1 A. The number of turns of the solenoid is 500 per metre. The magnetization of the material is nearly

• A. 2.5 x 103 A m-1
• B. 2.5x 105Am-1
• C. 2.0 x 103 A m-1
• D. 2.0 x 105 A m_1

Answer 1

Answer: (B)

2.5x 105Am-1

Answer 2

: Here, , turns/m,

$\mathrm { I } = 1 \mathrm {~A} , \mu _ { \mathrm { r } } = 500$

Magnetic intensity, ,

$\mathrm { H } = \mathrm { nI } = 500 \mathrm {~m} ^ { - 1 } \times 1 \mathrm {~A}$

As

where X is the magnetic susceptibility of the material or

$X = \left( \mu _ { r } - 1 \right)$

magnetisation, , M = XH

$= \left( \mu _ { \mathrm { r } } - 1 \right) \mathrm { H } = ( 500 - 1 ) \times 500 \mathrm { Am } ^ { - 1 }$

$= 2.5 \times 10 ^ { 5 } \mathrm { Am } ^ { - 1 }$