Question

A solenoid has a core of a material with relative permeability of 500. The windings of the solenoid are insulated from the core and carry a current of 2 A. If the number of turns is 1000 per meter, then magnetisation is

• A. 7.78 x 105 A m-1
• B. 8.88xl05Am-1
• C. 9.98 x 105 A m-1
• D. 10.2 x 10s A m-1

Answer 1

Answer: (C)

9.98 x 105 A m-1

Answer 2

: As $\mathrm { B } = \mu _ { 0 } ( \mathrm { M } + \mathrm { H } )$

Magnetization,

then ,

$\mathrm { M } = \frac { \mu _ { 0 } \mu _ { \mathrm { r } } \mathrm { H } - \mu _ { 0 } \mathrm { H } } { \mu _ { 0 } } = \left( \mu _ { \mathrm { r } } - 1 \right) \mathrm { H } \left( \because \mathrm { B } = \mu _ { 0 } \mu _ { \mathrm { r } } \mathrm { H } \right)$

Here, and

or $\mathrm { M } = 9.98 \times 10 ^ { 5 } \mathrm { Am } ^ { - 1 }$ .