In a series circuit carrying 2 A, what is the voltage across a 3 Ω resistor?

• A. 6 V
• B. 1.5 V
• C. 9 V
• D. 12 V

Answer: (A)

In a series circuit, the current is the same through every component, and the voltage across a resistor is found using V = I × R. With a current of 2 A through a 3 Ω resistor, the voltage drop across that resistor is 2 × 3 = 6 volts. So the resistor experiences 6 V. The other values would require different current or resistance; given the 2 A current, 3 Ω gives 6 V.