DP Physics (last assessment 2024)

Question 21M.2.SL.TZ2.b

Date	May 2021	Marks available	[Maximum mark: 3]	Reference code	21M.2.SL.TZ2.b
Level	SL	Paper	2	Time zone	TZ2
Command term	Calculate	Question number	b	Adapted from	N/A

[Maximum mark: 3]

21M.2.SL.TZ2.b

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

Calculate the internal resistance of the photovoltaic cell for the maximum intensity condition using the model for the cell.

[3]

Markscheme

ALTERNATIVE 1
pd dropped across cell $= 6.5 « V »$ ✓

internal resistance $= \frac{6.5}{0.9}$ ✓

$7.2 « Ω »$ ✓

ALTERNATIVE 2

$ε = I (R + r)$ so $ε = V + I r$ ✓