.. 2.10

Light dependent resistors
=========================

**Objective**

Learn about LDR. Measure intensity of light and its variation with
distance from the source.

.. image:: schematics/ldr.svg
	   :width: 300px

**Procedure**

-  Measure the LDR’s resistance, for different light intensities.
-  Iluminate LDR using a fluorescent lamp, A1 should show ripples
-  Put A1 in AC mode and measure ripple frequency

**Discussion**

The resistance vary from 1kΩ to around 100 kΩ depending on the intensity
of light falling on it. The voltage is proportional to the resistance.
The resistance decreases with intensity of light. If you use a point
source of light, the resistance should increase as the square of the
distance between the LDR and the light source.
