Which of the following statements about a photovoltaic (solar) cell is incorrect with reference to how it works and what it is used for?

Introduction / Context:
This question tests your conceptual understanding of what a photovoltaic cell is and how it functions. A photovoltaic cell is commonly known as a solar cell, and it is widely used to convert light energy from the Sun or other sources into electrical energy. Knowing which statements correctly describe a photovoltaic cell and which confuse it with other devices, such as light emitting diodes, is important for basic physics and general science awareness.

Given Data / Assumptions:

• We are dealing with a photovoltaic cell, commonly called a solar cell.
• The options mention names, detection of infrared radiation, energy storage and conversion of electric energy into light.
• We assume standard devices used in solar panels and photodetectors.
• Only one statement is meant to be incorrect, and we must identify it.

Concept / Approach:
A photovoltaic cell is a semiconductor device that converts light energy directly into electrical energy using the photovoltaic effect. It is indeed referred to as a solar cell when used with sunlight. Many photodiodes and photovoltaic cells are sensitive in the infrared region and can act as detectors for that radiation. However, a single photovoltaic cell does not act as an energy storage device; it generates electricity only while it is illuminated, and storage requires external batteries or capacitors. Most importantly, a photovoltaic cell does not convert electric energy into light energy. That is the function of devices such as light emitting diodes and lamps. Therefore the statement that it converts electric energy into light energy is incorrect for a photovoltaic cell.

Step-by-Step Solution:
Step 1: Recognise that photovoltaic cell and solar cell refer to the same basic device that converts light to electricity, so option A is correct. Step 2: Note that some photovoltaic and photodiode devices are designed to respond to infrared radiation as detectors, so option B can be considered correct in general scientific usage. Step 3: Understand that a photovoltaic cell produces electric energy only as long as light falls on it and does not store energy by itself; storage requires separate components, so stating that it cannot by itself store energy is correct, making option C a true statement. Step 4: Examine option D, which says that a photovoltaic cell converts electric energy into light energy. This is opposite of what a photovoltaic cell does and actually describes the behaviour of a light emitting diode or electric lamp. Step 5: Since a photovoltaic cell converts light energy into electrical energy, not the other way round, option D is incorrect. Step 6: Conclude that option D is the only incorrect statement about a photovoltaic cell.

Verification / Alternative check:
Consider a solar panel on a rooftop. When sunlight falls on it, it generates electric power that is then used to run loads or charge batteries. At night, when there is no light, the panel does not emit light or store energy internally; it simply remains inactive. This real world behaviour clearly matches the description of converting light into electrical energy and needing external storage systems. The panel does not glow or produce light when electricity is supplied to it, which confirms that converting electric energy into light is not its function.

Why Other Options Are Wrong or Right:
Option A is correct because the term photovoltaic cell is commonly used interchangeably with solar cell. Option B is correct because suitably designed photovoltaic and photodiode devices can act as infrared detectors in various instruments. Option C is correct because a photovoltaic cell generates but does not store energy; energy storage requires separate batteries or capacitors. Option D is incorrect because converting electric energy into light energy is the role of light emitting devices, not photovoltaic cells.

Common Pitfalls:
Students sometimes confuse photovoltaic cells with light emitting diodes or think that any device involving light and electricity can work in both directions. In reality, while some devices can operate reversibly under special conditions, the standard function of a photovoltaic cell is to convert light into electrical energy only. It is also easy to assume that because solar systems involve storage, the cell itself stores energy, which is not true. Remember that generation, detection and storage are different roles usually handled by different components.

Final Answer:
The incorrect statement is that a photovoltaic cell converts electric energy into light energy.