Bennett Mechanical Comprehension Practice Test 2025 – The Complete All-in-One Guide to Exam Success!

The component that restricts the flow of electric current to a single direction is known as a diode. Diodes are semiconductor devices that allow current to pass through them in one direction while blocking it in the opposite direction. This property is essential in various applications, including rectification processes in power supplies, where alternating current (AC) needs to be converted to direct current (DC).

Diodes function based on the principle of p-n junctions, where the flow of charge carriers is controlled. When the junction is forward-biased, current flows easily; when reverse-biased, the current is significantly reduced, ideally to zero. This unique characteristic of diodes makes them fundamental in electronic circuits for controlling current direction and protecting sensitive components from damage caused by reverse polarity.

In contrast, transistors are more complex components used for switching and amplification but do not inherently restrict current to one direction. Resistors reduce electrical current throughout a circuit but don’t control the direction of flow. Capacitors primarily store and release electrical energy, and while they can influence current flow within circuits, they do not provide unidirectional current flow like diodes do.