Superconductors expel a magnetic field from their bulk. In liquid N₂, 102.5 mg of a YBa₂Cu₃O_6.9 powder of apparent density 3000 kg/m³ was placed into the center of a miniature induction coil (a pick-up coil), and the induced voltage dropped by 450 mV. At 26 °C, a 38.4 mg standard increased the (empty-coil) voltage by 5.73 V. Assuming a linear voltage response to susceptibility, calculate the fraction of the magnetic field expelled from the inside of the superconductor, given that the standard was a Curie– Weiss paramagnet with C_m = 9.164×10⁻⁴ m³ K/kg and θ = −24 K. The expelled field corresponds to the dimensionless (volume) diamagnetic susceptibility of the superconductor. Because the samples were weighed, mass susceptibility must be calculated first.