1) Show diagramatically the behavior of magnetic field lines in the presence of (i) paramagnetic and (ii) diamagnetic substances. How does one explain this distinguishing feature.
2) Define intensity of radiation on the basis of photon picture of light. Write its S.I. unit.
1) Magnetic field lines preferably do not pass through diamagnetic substances as they have relative permeability less than 1.
Magnetic field lines preferably pass through paramagnetic substances as they have relative permeability greater than 1.
The following diagram is for you to better visualize the concept:
2) The energy related to photons emitted from a given surface area in a given amount of time is the definition of radiation intensity. S.I. Watt per steradian i.e., W sr-1 is the unit.
End of analysis. Great!