If the current through an electrical machine running on direct current is 15 A and the machine runs for 10 minutes, the charge that passes through the machine during this time is :

Charge Q = I × t. The current is 15 A and the time is 10 minutes = 600 seconds. Therefore Q = 15 × 600 = 9000 C. This is a direct application of the definition of electric current, which is the rate of flow of charge. Since the current is steady (direct current), the total charge is simply the product of current and time. Hence the correct answer is 9000 C.