The Potential Divider
One digital multimeter set on 20V dc (see diagram below), lab power supply set on 10V dc, two 10k resistance boxes, light dependent resistor, wires.
1. Set up the circuit shown above, with both resistor boxes,andset at
2. For a range of values ofrecord the value ofand calculate,
Note:should remain set atthroughout.
3. Tabulate your results and then plot a graph ofagainst
4. Calculate the gradient of your graph. Your gradient should equal the supply voltage. This may not be!
5. Replacewith the light dependent resistor.
Note and explain (using your previous results) why the voltage levels change as you change the level of light incident on the LDR.