The voltage appearing across the contacts after opening of the circuit breaker is called recovery voltage.
Answer : The arcing contacts in a circuit breaker are made of copper tungsten alloy.
Answer : The arc voltage produced in A.C. circuit breaker is always in phase with the arc current.
Description : The arc voltage in a circuit breaker is :
Answer : The arc voltage in a circuit breaker is : in phase with the arc current
Answer : The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to extinguish the arc.
Answer : In order that current should flow without causing excessive heating or voltage drop, the relay contacts should have low contact resistance, be clean and smooth, be of sufficient size and proper shape.