____ is the rms value of AC component of the current in the pole at the instant of contact separation.

• A. Asymmetrical breaking current
• B. Symmetrical short circuit current
• C. Making current
• D. Symmetrical breaking current

Answer: (D)

Symmetrical breaking current is the moment when fault occurs maximum fault current is observed and decays with respect to time.
Symmetrical breaking current = RMS value of ac component of short circuit current at the instant of separation of the contacts.
Symmetrical breaking capacity is less than asymmetrical breaking capacity.