Magnetism Question 253
Question: The magnetic field of earth at the equator i approximately $ 4\times {{10}^{-5}}T $ . The radius of earth is $ 6.4\times 10^{6}m $ . Then the dipole moment of the earth will be nearly of the order of:
Options:
A) $ 10^{23},A,m $
B) $ 10^{20},A,m^{2} $
C) $ 10^{16},A,m^{2} $
D) $ 10^{10},A,m^{2} $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Given, $ B=4\times {{10}^{-5}},T $
$ R _{E}=6.4\times 10^{6}m $ Dipole moment of the earth M=? $ B=\frac{{\mu _{0}}}{4\pi }\frac{M}{d^{3}} $
$ 4\times {{10}^{-5}}=\frac{4\pi \times {{10}^{-7}}\times M}{4\pi \times {{(6.4\times 10^{6})}^{3}}} $
$ \
Therefore ,,,,,,M\cong 10^{23},Am^{2} $
BETA
