Question

A magnetising field of 2 x 103 A m-1 produces a magnetic flux density of 8$\pi$ T in an iron rod. The relative permeability of the rod will be

• A. 102
• B. 1
• C. $10 ^ { 4 }$
• D. $10 ^ { 3 }$

Answer 1

Answer: (C)

$10 ^ { 4 }$

Answer 2

: Here, , $\mathrm { H } 2 \times 10 ^ { 3 } \mathrm { Am } ^ { - 1 } = 8 \pi \mathrm { T } , \mu _ { 0 } = 4 \pi \times 10 ^ { - 7 }$

Since ,

$\mu _ { \mathrm { r } } = \frac { \mu } { \mu _ { 0 } } = \frac { \mu \mathrm { H } } { \mu _ { 0 } \mathrm { H } } = \frac { \mathrm { B } } { \mu _ { 0 } \mathrm { H } } = \frac { 8 \pi } { 4 \pi \times 10 ^ { - 7 } \times 2 \times 10 ^ { 3 } }$