In a circuit with a source voltage of 45 volts and a resistance of 5 ohms, what is the circuit's current in amperes?

To find the current in the circuit, Ohm's Law is applied, which states that current (I) can be calculated by dividing the voltage (V) by the resistance (R). The formula is:

[ I = \frac{V}{R} ]

In this scenario, the voltage (V) is 45 volts, and the resistance (R) is 5 ohms. Plugging in these values:

[ I = \frac{45 \text{ volts}}{5 \text{ ohms}} = 9 \text{ amperes} ]

This calculation shows that the circuit's current is indeed 9 amperes. Thus, the answer is justified because it accurately reflects the application of Ohm’s Law to the given values in the question.