What is the voltage across a 10-ohm resistor if a current of 1 ampere flows through it?

To find the correct answer, you must apply Ohm's Law, which states that Voltage (E) equals Current (I) multiplied by Resistance (R). The standard formula is written as E = I x R. In this specific question, you are given a current of 1 ampere and a resistance of 10 ohms. Plugging these values into the formula gives E = 1 A x 10 Ω, which equals 10 volts. The other options are incorrect because they result from improper math. For example, 11 volts and 9 volts come from mistakenly adding or subtracting the current and resistance values rather than multiplying them.