A small filament lamp is positioned inside a light-tight box at a fixed distance from a light-dependent resistor (LDR). The lamp is connected to a variable electrical power source.
It is suggested that the relationship between the electrical power PPP dissipated by the lamp and the stable resistance RRR of the LDR is given by the expression:
R=aPbR = a P^bR=aPb
where aaa and bbb are constants.
Describe how an experiment can be conducted to test the validity of this expression and how the data collected can be analysed to determine the values of aaa and bbb.
In your description, you should specify:
- A circuit diagram to vary and measure the power of the lamp, and to determine the resistance of the LDR.
- The measurements to be taken.
- The control variables and precautions needed to ensure reliable results.
- How the data is analysed using a graph to find aaa and bbb.
