Question

Fuel cells produce electricity with an efficiency of about ________ percentage compared to thermal plants whose efficiency is about 40%.

Hint:

Tangents drawn at the ends of a diameter are always parallel because the diameter acts as a transversal perpendicular to both lines.

Answer 1

Concept:
Fuel cells convert chemical energy directly into electrical energy through electrochemical reactions. Unlike thermal power plants, they do not rely on combustion, which increases their efficiency.
Explanation:

Thermal power plants operate at about \(40%\) efficiency due to energy losses as heat.
Fuel cells can achieve efficiencies of about \(60% - 70%\).
When waste heat is utilized (combined heat and power systems), overall efficiency may exceed \(80%\). \[ \boxed{\text{Efficiency of fuel cells } \approx 70%} \]