when price of a commodity is fixed by the law either below or above the equilibrium, the mechanism is known as

The mechanism in which the government sets a legal price for a commodity that is either lower or higher than the market equilibrium price is known as "price control." Price controls are a form of government intervention in the market to protect consumers or producers, but they can have unintended consequences, such as shortages or surpluses of the commodity, black markets, and reduced incentives for production or investment. In a perfectly competitive market, prices are determined by the forces of supply and demand, and the market reaches an equilibrium price where the quantity supplied equals the quantity demanded. However, price controls interfere with this natural mechanism and can lead to distortions in the market.