One purpose of grounding the primary object to the primary structure?

• A. Prevent EMI
• B. Increase current capacity
• C. Reduce weight
• D. Improve thermal conduction

Answer: (A)

Grounding the primary object to the primary structure establishes a common electrical reference and a low-impedance path for unwanted currents. This helps shunt high-frequency noise and static charges into the airframe, reducing radiated and conducted EMI and keeping sensitive systems from experiencing interference.

It isn’t primarily about increasing current capacity—that depends on conductor size and the overall return path, not just bonding. It won’t significantly reduce weight, since adding a bonding strap adds some mass. And while a metal path can assist heat transfer, the main purpose here is noise and static control, not thermal conduction.