Diamagnetic material susceptibility χ is: MCQ with Answer and Explanation

Explanation:
100°C = 373.15 K, approximately 373 K. Freezing 273 K. No degree sign for Kelvin. Kelvin scale starts at absolute zero.

Explanation:
A transformer core is subject to alternating magnetic fields, tracing out a hysteresis loop repeatedly. To minimize energy loss (hysteresis loss), the area of this loop must be small, requiring low coercivity (easily demagnetized). It also requires low retentivity so it loses magnetism rapidly when current stops. Steel, conversely, has high retentivity and coercivity, used for permanent magnets.

Explanation:
Resistance depends on length and area (R = rho * L / A), but specific resistance or resistivity (rho) is an intrinsic property of the material itself. It does not depend on the geometric dimensions of the conductor (length, area, volume). Resistivity strictly depends on the atomic structure (nature of the material) and the thermal vibrations (temperature of the material).