Bt

There is no effect. Let's say the equilibrium price is $10 and the volume bought and sold at that price is 10,000 units. If there is a price ceiling of $12 the price will not move up because there is no demand for all 10,000 units at that price. If the price ceiling were set at $8 then manufacturers would make fewer units and buyers would want more of the cheap units. That would produce a shortage.