Which component allows current to flow in only one direction? The arrow of the circuit symbol shows the direction in which the current can flow.

Which component allows current to flow in only one direction? The arrow of the circuit symbol shows the direction in which the current can flow.

• A. Inductor
• B. Resistor
• C. Diode
• D. Capacitor

Answer: (C)

A diode is the component that allows current to flow in only one direction. Its symbol includes an arrow-like shape, and conventional current can pass from the anode toward the cathode only when the diode is forward-biased. When the voltage is reversed, it blocks current, which is why it’s used to rectify AC and protect circuits from reverse polarity. The other parts don’t enforce unidirectional flow: an inductor resists changes in current and can carry current in either direction; a resistor passes current in either direction according to Ohm’s law; a capacitor conducts current only during changing voltages and, in steady state, blocks DC, but it doesn’t provide a fixed one-way path like a diode.

A diode is the component that allows current to flow in only one direction. Its symbol includes an arrow-like shape, and conventional current can pass from the anode toward the cathode only when the diode is forward-biased. When the voltage is reversed, it blocks current, which is why it’s used to rectify AC and protect circuits from reverse polarity. The other parts don’t enforce unidirectional flow: an inductor resists changes in current and can carry current in either direction; a resistor passes current in either direction according to Ohm’s law; a capacitor conducts current only during changing voltages and, in steady state, blocks DC, but it doesn’t provide a fixed one-way path like a diode.