experiment

1. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
MALUS LAW
S MD SALMAN

2. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Outline
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and Conclusion

3. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Theory
Polarisation is the property of electromagnetic waves that
describes the orientation of their field oscillation.
In ordinary light, electric field vector vibrates in all directions
in a plane perpendicular to the direction of propagation.
This light is unpolarised light
.
Unpolarised light consists of electric field vectors in all
directions
If the electric field vectors of light vibrates just in one
direction perpendicular to the direction of wave propagation,
then its said to be Linearly polarised

4. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Theory
Since in a linearly polarised wave, the vibrations at all points
at all times lie in the same plane called PLANE POLARISED
WAVE
The Polariser is a device that plane polarises the unpolarised
light passed through it
Analyser is a device that analyses whether the light is
polarised or not.

5. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Principle
When a plane polarised light is seen through an analyser, the
intensity of transmitted light varies as the analyser is rotated
in its on plane.
MALUS discovered that When a beam of completely plane
polarised light is passed through analyser, the intensity I of
transmitted light through analyser varies directly as the
square of cosine angle between the transmission directions of
polariser and analyser. This is MALUS LAW.

6. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Formula
Mathematically, I directly proportional to cos2θ
I αcos2θ
ie I=I0cos2θ
Here, I0 is the maximum intensity of transmitted light.
Special cases
(a) When θ = 00or1800cosθ = + − 1 so that I=I0
ie When the transmission directions of polariser and analyser
are parallel or antiparallel to each other, the maximum
intensity of plane polarised light is transmitted by the
analyser and is equal to the intensity emerging from the
polariser.

7. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Formula
(b) When θ = 900, cosθ = 0, so that I=0
When the transmission directions of polariser and analyser
are perpendicular to each other, then the intensity of light
transmitted through the analyser is zero

8. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Experimental Setup

9. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion

10. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Procedure
The diode laser, analyser and detector are mounted on
optical bench.
The analyser is adjusted for maximum output in the
indicating unit(IU). Then the analyser is rotated
through a fixed angle and output of the IU is noted
Take the reading by varying analyser angle from 00 to
3600
plot the graph for I vs θ and I vs cos2θ

11. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Data
ANGLE COS2θ IUR
0 1 3.08
5 0.9924 3.07
10 0.9698 3.04
15 0.933 3.02
20 0.883 2.97
25 0.8214 2.9
30 0.75 2.81
35 0.671 2.7
40 0.5868 2.55
45 0.5 2.37
50 0.4132 2.09
55 0.329 1.8
60 0.25 1.44
65 0.1786 1.07
70 0.117 0.7

12. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Data
ANGLE COS2θ IUR
75 0.067 0.4
80 0.0301 0.19
85 0.0076 0.07
90 0 0.04
95 0.0076 0.12
100 0.0301 0.29
105 0.067 0.56
110 0.117 0.89
115 0.1786 1.25
120 0.25 1.63
125 0.329 1.93
130 0.4132 2.24
135 0.5 2.46
140 0.5868 2.64

13. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Data
ANGLE COS2θ IUR
145 0.671 2.78
150 0.75 2.88
155 0.8214 2.94
160 0.883 3
165 0.933 3.03
170 0.9698 3.06
175 0.9924 3.07
180 1 3.07
185 0.9924 3.06
190 0.9698 3.04
195 0.933 3
200 0.883 2.96
205 0.8214 2.9
210 0.75 2.81

14. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Data
ANGLE COS2θ IUR
215 0.671 2.7
220 0.5868 2.54
225 0.5 2.34
230 0.4132 2.04
235 0.329 1.71
240 0.25 1.34
245 0.1786 0.96
250 0.117 0.6
255 0.067 0.32
260 0.0301 0.14
265 0.0076 0.06
270 0 0.08
275 0.0076 0.22
280 0.0301 0.44
285 0.067 0.76
290 0.117 1.13

15. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Data
ANGLE COS2θ IUR
295 0.1786 1.53
300 0.25 1.9
305 0.329 2.19
310 0.4131 2.41
315 0.5 2.59
320 0.5868 2.74
325 0.671 2.84
330 0.75 2.92
335 0.8214 2.98
340 0.883 3.03
345 0.933 3.06
350 0.9698 3.08
355 0.9924 3.08
360 1 3.08

16. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Graphs

17. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Graphs

18. MALUS LAW
S MD SALMAN
Theory
principle
Formula
Experimental setup
Procedure
Model Graphs
Tabular Column
Result and
Conclusion
Result Conclusion
Plotted the graphs for I vs θ I vs cos2θ
Malus Law has been verified
Conclusion Intensity of the transmitted light through
analyser varies cosine square of angle between optic axis
and polariser