Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The magnetic field of earth at the equator is approximately \( 4 \times 10^{-5} \mathrm{~T} \). The radius of earth is \( 6.4 \times 10^{6} \mathrm{~m} \). Then the dipole moment of the earth will be nearly of the order of :
PhysicsMagnetic Properties of MatterJEE Main
Options:
  • A \( 10^{20} \mathrm{Am}^{2} \)
  • B \( 10^{16} \mathrm{Am}^{2} \)
  • C \( 10^{10} \mathrm{Am}^{2} \)
  • D \( 10^{23} \mathrm{Am}^{2} \)
Solution:
1315 Upvotes Verified Answer
The correct answer is: \( 10^{23} \mathrm{Am}^{2} \)

B = μ 0 4 π · M d 3 = 1 0 - 7 × M 6.4 × 1 0 6 3
∴    4 × 1 0 - 5 = 1 0 - 7 × M 6.4 × 1 0 6 3
∴    M = 6.4 × 1 0 6 3 × 4 × 1 0 - 5 1 0 - 7
          = 6.4 3 × 1 0 1 8 × 4 × 1 0 2
          = 6.4 3 × 4 × 1 0 2 0
          = 1 . 0 4 8 × 1 0 2 3 10 23  A m 2

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.