Question

The equatorial magnetic field of earth is 0.4 G. Then its dipole moment on equator is

• A. 1.05 x 1023 A m2
• B. 2.05 x 1023 Am2
• C. 1.05 x 1021 Am2
• D. 2.05 x l021Am2

Answer 1

Answer: (A)

1.05 x 1023 A m2

Answer 2

: Here, , $\mathrm { b } _ { \mathrm { E } } = 0.4 \mathrm { G } = 0.4 \times 10 ^ { - 4 } \mathrm {~T}$

As (pwˇfd), $B _ { E } = \frac { \mu _ { 0 } } { 4 \pi r ^ { 3 } }$

$\therefore$

$= \frac { 0.4 \times 10 ^ { - 4 } \times \left( 6.4 \times 10 ^ { 6 } \right) ^ { 3 } } { 10 ^ { - 7 } }$