Answer:
(a) the subtransient current through the breaker in per-unit and in kA rms = 71316.39kA
(b) the rms asymmetrical fault current the breaker interrupts, assuming maximum dc offset. = 152KA
Explanation:
check the attached files for explanation
Answer:
the surface heat-transfer coefficient due to natural convection during the initial cooling period. = 4.93 w/m²k
Explanation:
check attachement for answer explanation
Answer and Explanation:
Commutator are used in DC machine commutator is mainly used for the reversing the direction of the current .It is connected to the armature of the DC generator or motor
ADVANTAGE OF COMMUTATOR The main advantage of the commutator in DC motor is to keep keep the direction of the toque always in the same direction by changing the current direction
DISADVANTAGE OF COMMUTATOR : The main disadvantage is due to the friction between the commutator and brushes there is a friction loss.