Solar energy is converted into electric energy through

1. A

   Dry cells

   Dry cells claim to convert chemical energy into electrical energy through an electrolyte paste, which is not designed for harnessing solar radiation.

2. B

   Leclanche cells

   Leclanche cells claim to generate electricity via a chemical reaction involving ammonium chloride and zinc, making them distinct from solar conversion devices.

3. C

   Voltaic cells

   Voltaic cells claim to produce electrical energy from chemical reactions between two different metals immersed in an electrolyte, rather than utilizing photovoltaic principles.

4. D

   Photo voltaic cells

   Photo voltaic cells claim to directly convert sunlight into electricity using semiconductor materials like silicon, which is the exact mechanism for solar energy conversion and makes this the correct key.

Summary. Official key is (d) Photo voltaic cells. Solar energy conversion relies on semiconductor devices that absorb photons and release electrons. Dry, Leclanche, and Voltaic cells instead rely on internal chemical reactions. Therefore, only photo voltaic cells serve the specific function of converting solar radiation into usable electrical power.