Question 21M.2.SL.TZ2.c
| Date | May 2021 | Marks available | [Maximum mark: 3] | Reference code | 21M.2.SL.TZ2.c |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Determine | Question number | c | Adapted from | N/A |
A photovoltaic cell is supplying energy to an external circuit. The photovoltaic cell can be modelled as a practical electrical cell with internal resistance.
The intensity of solar radiation incident on the photovoltaic cell at a particular time is at a maximum for the place where the cell is positioned.
The following data are available for this particular time:
Operating current = 0.90 A
Output potential difference to external circuit = 14.5 V
Output emf of photovoltaic cell = 21.0 V
Area of panel = 350 mm × 450 mm
The maximum intensity of sunlight incident on the photovoltaic cell at the place on the Earth’s surface is 680 W m−2.
A measure of the efficiency of a photovoltaic cell is the ratio
Determine the efficiency of this photovoltaic cell when the intensity incident upon it is at a maximum.
[3]
power arriving at cell = 680 x 0.35 x 0.45 = «107 W» ✓
power in external circuit = 14.5 x 0.9 = «13.1 W» ✓
efficiency = 0.12 OR 12 % ✓
Award [3] marks for a bald correct answer
Allow ECF for MP3
