The permeability of molding sand was determined using a saturated $$AFS$$ sample by passing $$2000cc$$ of air at a gage pressure of $$10$$ $$g/c{m^2}$$. If the time taken for the air to escape was $$1$$ min, the permeability number is:

Match the cast defect with their cause

According to Chvorinove's rule, the solidification time of a casting is proportional to [Volume/Surface area]ⁿ where $$n=....$$