GATE 2021 MT – Question 30
Iron’s room-temperature saturation magnetization is 1700 kA/m and lattice parameter 0.287 nm. Its per-atom magnetic moment is ______ $\times10^{-23}$ A·m$^2$ (one decimal place).
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 1.7 to 2.3
Explanation
BCC iron has two atoms per cell, volume per atom a³/2. Moment per atom is Ms a³/2=1.7×10⁶(0.287×10⁻⁹)³/2=2.0095×10⁻²³ A·m². Requested coefficient is **2.0**.