Q.Equilibrium condition of a firm is :

A firm's equilibrium (profit-maximising) condition is MC = MR.

A firm keeps expanding output as long as each extra unit adds more to revenue than to cost (MR > MC), and it will not produce a unit that costs more than it earns (MC > MR). Profit is therefore maximised at the output where the two are equal, MC = MR (with MC rising, i.e. cutting MR from below). This is the first-order condition of firm equilibrium under al …