_____ cell converts light energy directly into electric energy.

Photovoltaic

The correct answer is option 1. Photovoltaic.

A photovoltaic cell, commonly known as a solar cell, is a device that converts light energy directly into electrical energy through a process called the photovoltaic effect.

Here's how the photovoltaic effect works:

1. Absorption of Photons: Solar cells are typically made of semiconductor materials such as silicon. When sunlight (composed of photons) strikes the surface of the solar cell, the semiconductor material absorbs the photons.

2. Generation of Electron-Hole Pairs: When photons are absorbed by the semiconductor material, they transfer their energy to electrons in the material, causing them to become excited and break free from their atomic bonds. This process creates electron-hole pairs, where the electron is free to move, leaving behind a positively charged hole.

3. Separation of Charges: Due to the internal structure of the semiconductor material, the excited electrons and the positively charged holes are separated within the cell, creating an electric field. This electric field acts as a barrier, preventing the electrons and holes from recombining.

4. Generation of Electric Current: The separated charges (electrons and holes) are then collected by metal contacts on the surface of the solar cell. The flow of electrons through an external circuit generates an electric current, which can be used to power electrical devices or stored in batteries for later use.

5. Conversion of Light Energy to Electrical Energy: Overall, the photovoltaic effect enables the conversion of light energy (sunlight) directly into electrical energy (electricity), without the need for any moving parts or external fuel sources. This makes photovoltaic cells a clean and renewable source of energy.

Photovoltaic cells are widely used in solar panels, which are installed on rooftops, in solar farms, and even in smaller applications like calculators and outdoor lights. They play a crucial role in harnessing solar energy and reducing dependence on fossil fuels for electricity generation.