Which component is commonly used in circuits to control or limit current?

• A. Capacitor
• B. Resistor
• C. Battery
• D. Wire

Answer: (B)

Controlling current in a circuit is done mainly with a resistor. A resistor adds a specific amount of resistance, and according to Ohm’s law, the current flowing through a circuit is the voltage divided by that resistance. By choosing an appropriate resistance value, you can reduce the amount of current that reaches other components, protecting them from overheating or damage and allowing devices like LEDs to operate safely at the right brightness. Resistors are commonly placed in series with components to set current levels or in networks to create desired voltages.

Capacitors store charge and affect how current changes over time, rather than setting a steady current level. Batteries provide voltage, not current limitation, and wires simply conduct with very low resistance.