Which component is used primarily to limit current by providing resistance?

Which component is used primarily to limit current by providing resistance?

• A. Diode
• B. Light bulb
• C. Resistor
• D. Variable resistor

Answer: (C)

Resistors are used to limit current by introducing a defined resistance into a circuit. The current that flows through a circuit with a fixed supply and a resistor follows Ohm’s law: I = V/R. By selecting the resistance value, you set the current to a safe level for other components. For example, in an LED circuit with a 5V supply and an LED that drops about 2V, aiming for 10 mA of current would require a resistor around (5 − 2) / 0.01 = 300 ohms. A diode mainly controls the direction of current, not how much current flows. A light bulb acts as a load whose resistance changes with temperature and isn’t a stable current limiter. A variable resistor can adjust current, but a fixed resistor is the standard device used to provide a precise, unchanging limit.

Resistors are used to limit current by introducing a defined resistance into a circuit. The current that flows through a circuit with a fixed supply and a resistor follows Ohm’s law: I = V/R. By selecting the resistance value, you set the current to a safe level for other components. For example, in an LED circuit with a 5V supply and an LED that drops about 2V, aiming for 10 mA of current would require a resistor around (5 − 2) / 0.01 = 300 ohms. A diode mainly controls the direction of current, not how much current flows. A light bulb acts as a load whose resistance changes with temperature and isn’t a stable current limiter. A variable resistor can adjust current, but a fixed resistor is the standard device used to provide a precise, unchanging limit.