Why shields made of iron usually provided around precision instruments?

عام طور پر صحت سے متعلق آلات کے آس پاس فراہم کردہ لوہے سے بنی ڈھالیں کیوں؟

For guarding the instruments against unauthorized handing

For protection against the effect of external magnetic fields

For protection against the effect of moisture in the air

None of these

Iron is a magnetic material that can absorb and redirect magnetic field lines.

It shields precision instruments from external magnetic interference that could affect their accuracy.