What term describes a physical limit placed on the amount of imports allowed into a country?

The correct term for a physical limit placed on the amount of imports allowed into a country is "quota." A quota specifically refers to a government-imposed restriction that sets a limit on the volume of a specific product that can be imported into a country during a given timeframe. Quotas are often used to protect domestic industries from foreign competition by controlling the quantity of goods that can enter the market, thus helping to stabilize prices and support local production.

Other terms have different meanings. A tariff refers to a tax imposed on imported goods, which makes imported items more expensive, but does not directly limit their quantity. A subsidy is financial assistance provided by the government to encourage the production or consumption of certain goods, which is unrelated to import limits. A tax is a mandatory financial charge imposed by a government, but it does not specifically regulate the volume of imports entering a country. Thus, quota precisely captures the notion of a cap on the amount of imports.