Which method of generating an electrical current involves applying pressure?

• A. Friction
• B. Heat
• C. Pressure
• D. Light

Answer: (C)

The method of generating an electrical current through the application of pressure is known as piezoelectricity. This phenomenon occurs in certain materials that generate an electric charge in response to mechanical stress or pressure applied to them. When pressure is exerted on these piezoelectric materials, their internal structure changes, resulting in the production of electric voltage.

In practical applications, piezoelectric devices are commonly used in sensors, actuators, and energy harvesting technologies. Examples can include piezoelectric crystals used in microphones or pressure sensors where mechanical pressure is converted into an electrical signal, demonstrating the efficiency and role of pressure in generating electrical current.

The other methods listed, such as friction, heat, and light, generate electrical currents via different principles (triboelectric effects, thermoelectric effects, and photovoltaic effect, respectively), but they do not specifically relate to the direct application of pressure in the same way that the piezoelectric effect does.