What is the name for a one way electrical switch?

What is the name for a one way electrical switch?

• A. Diode
• B. Relay
• C. Transistor
• D. Fuse

Answer: (A)

The key idea here is a device that conducts current in one direction while blocking it in the opposite direction. A diode fits this description perfectly: it conducts readily when the anode is more positive than the cathode (forward bias) and blocks current when the polarity is reversed (reverse bias). That creates a one-way path for current, like a gate that lets electricity through in one direction but not the other. This behavior is why diodes are widely used in rectifiers and polarity protection. Relays are mechanical switches controlled by a coil, not inherent one-way conduction. Transistors act as switches with gain and have three terminals, not simply a one-way current gate. Fuses protect by opening the circuit under overcurrent, not by directing current in one direction.

The key idea here is a device that conducts current in one direction while blocking it in the opposite direction. A diode fits this description perfectly: it conducts readily when the anode is more positive than the cathode (forward bias) and blocks current when the polarity is reversed (reverse bias). That creates a one-way path for current, like a gate that lets electricity through in one direction but not the other. This behavior is why diodes are widely used in rectifiers and polarity protection.

Relays are mechanical switches controlled by a coil, not inherent one-way conduction. Transistors act as switches with gain and have three terminals, not simply a one-way current gate. Fuses protect by opening the circuit under overcurrent, not by directing current in one direction.