When is equilibrium reached? . a-when supply is greater than demand. b-when demand equals supply. c-when supply is less than demand. d-when demand and supply both change.

Option (B) is the correct answer.

Explanation:

Equilibrium is defined as the state where demand and supply are equal to each other.

For example, a shopkeeper had 100 goods and all of them got sold in two days. Rest of the goods were kept by the shopkeeper in stock.

Hence, it shows that the shopkeeper has fulfilled the demand of customers by supplying them the goods.

Therefore, we can conclude that when demand equals supply then it means an equilibrium has reached.

snell's law

refractve index = sin incidence / sin refraction