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

This question requires you to apply Ohm's Law, which states that voltage equals current multiplied by resistance (E = I x R). E represents voltage, I is current in amperes, and R is resistance in ohms. By substituting the numbers provided in the question, you get E = 1 ampere x 10 ohms. Any number multiplied by one is itself, making the correct calculation exactly 10 volts. The distractors in this question test whether you know the correct formula. If you were to incorrectly add the values you would get 11, or if you subtracted them you would get 9, neither of which follows Ohm's Law.