For a circuit breaker to protect anything, it must be wired in series with whatever it is protecting.
== == == == == == To open a circuit during an overcurrent event, thus protecting the cabling and devices connected to it.
it is connected in a box
In principle, it is infinite. I have not connected a parallel circuit in ages.
It should be connected to circuit breaker. Circuit breaker will automatically discontinue the flow of electricity if it detects faulty condition.
circuit breakers are connected in series manner in the circuit.
Yes. The circuit breaker "does not care" which direction the current comes from. It is capable of protecting the circuit in any case.
Parallel to each other.
A GFCI device in a breaker is intended to trip the breaker open when a ground fault is sensed in the circuit that the breaker is protecting.
A circuit in which loads are connected side by side is known as a parallel circuit.
If additional resistance is connected in parallel with a circuit the supply voltage will decrease?
No change in supply voltage as additional resistance is connected in parallel circuit.
If the test shows that there is a continuity between the phase leg and the neutral with no load connected, then that circuit should not be energized. If the circuit was energized then the fuse or breaker protecting that leg will trip the circuit open.