A rod of ferromagnetic material with dimensions 10 cm×0.5 cm×0.2 cm is placed in a magnetic field of strength $0.5×10^4 amp/m$ as a result of which a magnetic moment of $5 amp-m^2$ is produced in the rod. The value of magnetic induction will be-
Answer & explanation
Correct answer: option 4
$ B = \mu_0 (I+H) = \mu_0 (\frac{M}{V} + H) = 4\pi \times 10^{-7} (\frac{5}{10^{-6}} + 5000) = 6.28T$