Which of the following does not cause permanent damage of an $$SCR?$$

Figure, show two thyristors each rated $$500A$$ (continuous) sharing a load current. Current through thyristor $$y$$ is $$120A.$$ The current through thyristor $$x$$ will be nearly __________ $$A.$$

A switched mode power supply operating at $$20$$ $$kHz$$ to $$100$$ $$kHz$$ range uses as the main switching element

A triac can be triggered by a gate pulse of __________ polarity