JKSSB Written 2018
Answer & Explanation
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Correct Answer:
Option A —
Photovoltaic cells
Why "Photovoltaic"?The term comes from the Greek word phos, meaning "light," and the name of the physicist Alessandro Volt.
Mechanism: Photovoltaic (PV) cells are electronic devices that convert sunlight directly into electricity using the photovoltaic effect. When sunlight hits the semiconducting material (usually silicon) inside the cell, it knocks electrons loose, creating an electric current.
Structure: Multiple solar cells are connected to form a solar panel, and multiple panels can be linked to create a solar array.
Why the other options are incorrect:
Dry cells (B): These are standard batteries (like the ones in your TV remote) that use a paste electrolyte rather than a liquid. They store chemical energy, they don't generate it from light.
Galvanic cells (C): Also known as voltaic cells, these derive electrical energy from spontaneous chemical reactions (like a car battery).
Electrochemical cells (D): This is a broad category that includes any device capable of either generating electrical energy from chemical reactions or using electrical energy to cause chemical reactions.
Solar Power in India
Because India is a tropical country, it receives about 5,000 trillion kWh of solar energy per year. The government has pushed for PV cells in remote areas because they are:
Low Maintenance: No moving parts means they last a long time.
Scalable: You can have one small panel for a single light or a massive "Solar Park" for an entire city.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.