There is no positive level of output that a firm generates at which price is not equal to MC. Let us understand the following two cases where price is not equal to MC.
Case A: If P > MC
At output Oq1, price is, while the MC is Lq1. So, Oq1 isn't the income maximizing output. that is because of the truth that the firm can grow its profit degree via increasing its output too.
Case B: If P < MC
At output Oq3 price is Hq3 and MC is Gq3. So, Oq3 isn't always the income maximizing output. That is due to the fact the firm can growth its income through lowering its output degree to. Hence the earnings maximizing factor must be same as MC and it can not be extra or lesser than MC.