What is the voltage drop across R1 if its value is 5 volts?

The voltage drop across a resistor is determined by the potential difference across that resistor. In this case, if the value of R1 is given as 5 volts, then this indicates that there is a voltage drop of exactly 5 volts across it. This is consistent with Ohm's Law, which states that voltage (V) is equal to the current (I) flowing through a resistor multiplied by the resistance (R). When we designate a specific voltage for a resistor, it means that this is the potential difference that exists across it when a current flows.

In the context of this question, since R1 is specified to have a voltage of 5 volts, that aligns directly with the definition of voltage drop, confirming that the drop across R1 is indeed 5 volts. This makes the provided answer accurate.