Researchers investigate how the magnetic properties of an unknown metallic sample…
PHYSICS · Multi-part · CBSE · Physics · Magnetism and Matter · Magnetism and Matter
Problem
Researchers investigate how the magnetic properties of an unknown metallic sample change with temperature. The sample is placed in the center of a calibrated solenoid connected to a constant-current power supply. A Hall probe fixed at the solenoid’s center records the magnetic flux density B.
With no sample present and a current of 1.5 A, the probe reads 12.0 mT. With the sample inserted, the probe readings are:
• Room temperature (25 °C): 16.8 mT
• 600 °C: 12.7 mT
• 900 °C: 12.1 mT
Assume the magnetizing field generated by the solenoid is independent of the presence of the sample.
(a) For each temperature, determine the relative permeability μr of the sample.
(b) Using the calculated values, classify the magnetic behavior of the sample at each temperature.
(c) Estimate a temperature interval within which the sample’s Curie temperature likely lies, and justify your estimate.
(d) Propose a method to test whether any magnetization that the sample acquires at 25 °C is permanent or merely induced. Describe the expected observations for each possibility.
(e) Identify two significant sources of experimental uncertainty in this investigation and discuss how each could affect the calculated values of μr. Suggest one improvement for reducing each uncertainty.