ARRL Technician Practice Exam 2026 - Free Technician License Practice Questions and Study Guide

To determine the voltage across a resistor when you know the current flowing through it and its resistance, you can use Ohm's Law, which states that Voltage (V) equals Current (I) multiplied by Resistance (R). The formula is expressed as:

\[ V = I \times R \]

In this case, the current (I) is 1 ampere, and the resistance (R) is 10 ohms. Plugging in these values:

\[ V = 1 \, \text{A} \times 10 \, \Omega = 10 \, \text{V} \]

This calculation shows that the voltage across the 10-ohm resistor is indeed 10 volts. Understanding Ohm's Law is crucial for working with electrical circuits, as it allows you to calculate the relationship between voltage, current, and resistance in a straightforward manner.

The other options (5 volts, 15 volts, and 20 volts) do not derive from the values provided in the question. Using the correct application of Ohm's Law, only 10 volts accurately represents the voltage across the resistor given the specified current and resistance.