If a circuit has an operating voltage of 220 volts and resistance of 55 ohms, what total resistance is needed to limit the current to 2 amperes?

• A. 110 Ω
• B. 55 Ω
• C. 220 Ω
• D. 44 Ω

Answer: (A)

To determine the total resistance needed to limit the current to 2 amperes in a circuit with an operating voltage of 220 volts, we can use Ohm's Law, which states that Voltage (V) = Current (I) × Resistance (R). Rearranging this formula allows us to solve for resistance: R = V / I.

In this situation, the voltage is 220 volts, and we want the current to be 2 amperes. Plugging these values into the rearranged formula gives us:

R = 220 volts / 2 amperes = 110 ohms.

This calculation indicates that a total resistance of 110 ohms is necessary to maintain the desired current of 2 amperes. This means that the correct answer reflects the additional resistance required in the circuit to ensure that the current does not exceed the specified limit, aligning with Ohm's Law for a simple linear circuit.

For context, the other answers do not yield the required current. 55 ohms would allow a current of 4 amperes (220V / 55Ω), which exceeds the limit. Similarly, 220 ohms would limit the current significantly below 2 amperes (0.5 amperes), while 44