Question

Essential difference between electrostatic shielding by a conducting shell and magnetostatic shielding is due to

• A. lines of $\overrightarrow{B}$ can also end but conductors cannot end them.
  
  
• B. electrostatic field lines can end on charges and conductors have free charges.
  
  
• C. shells of high permeability materials can be used to divert lines of $\overrightarrow{B}$ from the interior region.
• D. lines of $\overrightarrow{B}$ cannot end on any material and perfect shielding is not possible
  
  
  
  

Answer 1

Answer: (B), (C), (D)

lines of $\overrightarrow{B}$ cannot end on any material and perfect shielding is not possible

Electrostatic shielding is a method of shielding or protecting a particular region or space or any instrument from the effect of the external field produced by an electric charge.

A conducting shell obstructs the effect of external electric field on the contents of the interior whereas the same is also applied for the internal content which as not connection with the external environment.

Magnetic shielding is a phenomenon of protection of a region against any external magnetic effects. Magnetic field lines do not have any end or beginning as they are continuous loops and they pass through the conductor.

In this shielding, the object is kept in a cage or barrier made up of high permeability magnetic substance to cease the effect of external magnetic field on the object on the external environment

Unlike the electric shielding, the magnetic field is not completely blocked but passes around the enclosure.

Hence, we can only lower the influence of the magnetic field by placing high permeability materials.

Final Answer: (a), (c), (d)