For protecting a sensitive equipment from external magnetic field, it should be
A) Placed inside an iron can
B) Placed inside an aluminium can
C) Surrounded with fine copper sheet
D) Wrapped with insulation around it when passing current through it

Hint:
This problem is based on Magnetism and matter for which we must know the concept of magnetic screening that varies with different parameters and directions hence, analyze each & every option given with the scientific approach and check which option seems to be more appropriate for the given situation to present the answer with proper explanation.



Complete step by step solution:
According to the concept of Magnetic screening, we know that to protect any kind of sensitive element from magnetic field lines (or magnetic lines of forces), we have to shield that element in a substance that provides a hindrance to the path of magnetic field lines trying to reach the element.
The material used in this concept of magnetic screening is ferromagnetic as there are no magnetic field lines inside such elements.
Among the given options, Iron is a ferromagnetic element that can protect the element placed inside it.
Thus, for protecting a piece of sensitive equipment from the external magnetic field, it should be placed inside an iron can.
Hence, the correct option is (A) Placed inside an iron can.




Therefore, the correct option is A.




Note:
Since this is a problem related to Magnetism (conceptual problem) hence, it is essential that given options must be analyzed very carefully to give a precise explanation. While writing an explanation for this kind of conceptual problem, always keep in mind to provide the exact reasons in support of your explanation.