In which one of the following devices, the light energy is converted i

In which one of the following devices, the light energy is converted into the electrical energy?

Light-emitting diode
Laser diode
Solar cell
Transistor
This question was previously asked in
UPSC NDA-2 – 2022
The correct option is C, the Solar cell.
The question asks for a device where light energy is converted into electrical energy. This process is known as the photovoltaic effect.
– Light-emitting diode (LED) converts electrical energy into light energy.
– Laser diode also converts electrical energy into coherent light energy.
– Solar cell (photovoltaic cell) is specifically designed to absorb photons from sunlight and convert their energy into an electric current.
– Transistor is a semiconductor device used as an electronic switch or amplifier; it controls the flow of electrical current but does not primarily convert light energy to electrical energy (though some transistors can be light-sensitive, their main function isn’t energy conversion).
Therefore, the solar cell is the device that converts light energy into electrical energy.
Solar cells are the fundamental components of solar panels, which are widely used for generating renewable electricity. They are made of semiconductor materials, typically silicon, which release electrons when struck by photons of light, creating an electric current. This phenomenon is the basis of solar power generation.