These conduct electricity in only one direction.

These conduct electricity in only one direction.

• A. Diodes
• B. Resistors
• C. Capacitors
• D. Inductors

Answer: (A)

One-way conduction is the defining feature of a diode. A diode uses a PN junction that conducts readily when it is forward-biased—allowing current to flow—while it blocks current when reverse-biased, preventing flow in that direction. In forward bias, you get current with a small voltage drop (about 0.6–0.7 V for silicon); in reverse bias, current is nearly halted aside from tiny leakage. This unidirectional behavior is why diodes are used for rectification and protection. Resistors pass current in both directions with the same resistance, capacitors briefly conduct as they charge but then block steady DC, and inductors oppose changes in current but do not inherently enforce a single direction.

One-way conduction is the defining feature of a diode. A diode uses a PN junction that conducts readily when it is forward-biased—allowing current to flow—while it blocks current when reverse-biased, preventing flow in that direction. In forward bias, you get current with a small voltage drop (about 0.6–0.7 V for silicon); in reverse bias, current is nearly halted aside from tiny leakage. This unidirectional behavior is why diodes are used for rectification and protection. Resistors pass current in both directions with the same resistance, capacitors briefly conduct as they charge but then block steady DC, and inductors oppose changes in current but do not inherently enforce a single direction.