The aim of this experiment is to investigate the intensity of the light coming through two crossed polaroids and to verify Malus' Law.
WHAT TO DO
Set up the apparatus as shown.
Keeping one piece of polaroid fixed rotate the other.
Record the values of the current (I) through the LDR and the angle of rotation of the piece of polaroid (A).
ANALYSIS AND CONCLUSIONS
Plot a graph of I against cos2A
Deduce the relationship between I and A.
What have you assumed about the LDR?
Check this using a set of calibration tables.