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AP EAMCET · PHYSICS · Magnetic Properties of Matter

A short bar magnet has a magnetic moment of \(0.48 \mathrm{~J} \mathrm{~T}^{-1}\). The magnitude of magnetic field at a point at 10 cm distance from the centre of the magnet on its axis is

  1. A 0.96 gauss
  2. B 0.48 gauss
  3. C 1.92 gauss
  4. D 1.44 gauss
Verified Solution

Answer & Solution

Correct Answer

(A) 0.96 gauss

Step-by-step Solution

Detailed explanation

\(B = \frac{\mu_0}{4\pi} \frac{2M}{r^3}\) \(B = (10^{-7} \mathrm{~T \cdot m / A}) \frac{2 \times 0.48 \mathrm{~J \cdot T^{-1}}}{(0.1 \mathrm{~m})^3}\) \(B = 9.6 \times 10^{-5} \mathrm{~T}\) \(B = 9.6 \times 10^{-5} \times 10^4 \mathrm{~Gauss}\) \(B = 0.96 \mathrm{~Gauss}\)