Assertion: To protect any instrument from external magnetic field, it is put inside an iron body.
Reason: Iron is a magnetic substance.

To shield an instrument from external magnetic field, it is placed inside a cabin made of

Assertion : Any instrument can be protected from external magnetic field by putting inside a wooden box. Reason : Iron is a magnetic substance.

For protecting a sensitive equipment form external magnetic field, it should be

For protecting a sensitive equipment from the external magnetic field, it should be

For protecting a sensitive equipment from the external magnetic field, it should be

How can we protect delicate instruments from external electric field?