A technician uses a light sensor to choose where to place a tray of cress seedlings beneath a fixed lamp. The sensor measures only light from the lamp.
At 12 cm from the lamp, the sensor records a light intensity of III.
Light intensity is inversely proportional to the square of the distance from the lamp. I∝1d2I \propto \dfrac{1}{d^2}I∝d21
The sensor can be placed at 3 cm, 24 cm, 48 cm or 192 cm from the lamp.
What distance from the lamp gives a light intensity of I16\dfrac{I}{16}16I?
192 cm192\ \text{cm}192 cm
3 cm3\ \text{cm}3 cm
24 cm24\ \text{cm}24 cm
48 cm48\ \text{cm}48 cm
117 exam-style questions on OCR GCSE Biology 1.4 Photosynthesis, covering 1.4.1 Photosynthesisers as biomass producers, 1.4.2 Factors affecting the rate of photosynthesis, and 1.4.3 Limiting factors in photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.