The height of the down sprue is $$175$$ $$mm$$ and its $$CS$$ area at the base is $$200\,\,m{m^2}.$$ The $$CS$$ area of the horizontal runner is also $$200$$ $$m{m^2}$$. Assuming no losses, indicate the correct choice for the time (seconds) required to fill a mold cavity of volume $${10^6}\,\,m{m^3}.$$ (use $$g=10$$ $$m/{s^2}$$)

A $$10$$ $$mm$$ thick steel bar is to be horizontally cast with two correctly spaced top risers of adequate feeding capacity. Assuming end effect without chill, what should be the theoretical length of the bar?

Match the cast defect with their cause