Concept:The open-circuit voltage \( V_{\text{oc}} \) of a single PN junction solar cell is fundamentally limited by the semiconductor bandgap (\( E_g = 1.1\text{ eV} \) for Si) and is typically between 0.5 V and 0.6 V at room temperature.
Formula:$$V_{\text{oc}} = \frac{k T}{q} \ln\left(\frac{I_L}{I_0} + 1\right) \approx 0.5\text{–}0.6\text{ V} \quad (\text{for Silicon})$$
Solution:- A single silicon photovoltaic cell generates an open-circuit voltage of approximately \( 0.55\text{ V} \approx 0.5\text{–}0.6\text{ V} \) under standard illumination (\( 1000\text{ W/m}^2 \)).
- To achieve higher usable voltages (e.g., 12 V or 24 V), multiple individual solar cells are connected in series within a solar panel module.
Why other options are incorrect:- Option A: 0.1 to 0.2 V is too low and typical only for low-efficiency experimental junctions or Germanium under weak light.
- Option B: 1.5 to 2.0 V requires multi-junction tandem cells or wide-bandgap materials like GaInP.
- Option D: 12.0 to 14.0 V is the output of a complete solar panel comprising 24 to 36 cells in series, not a single cell.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.