Question

Suppose you have three polarizing filters through which light is passing. The second is oriented with its transmission axis at an angle of 34° with respect to the first one. The third polarizer is oriented at an angle of 90° with respect to the first. What percentage of the original intensity of unpolarized light will the final intensity have after passing through all three filters?

Answer 1

The final intensity of the light passing through all three filters will be zero.

Step-by-step explanation:

When unpolarized light passes through a polarizing filter, its intensity decreases by a factor of 2. In this case, we have three polarizing filters arranged at different angles. The first filter polarizes the light along its axis, decreasing its intensity by half. The second filter is oriented at an angle of 34° with respect to the first, allowing only a component of the light parallel to its axis to pass through. Finally, the third filter is oriented at an angle of 90° with respect to the first, blocking all the remaining light. Therefore, the final intensity of the light passing through all three filters will be zero.

Using the law of Malus, the final intensity of light after passing through three polarizing filters is calculated to be 0% of the original intensity when the third filter is oriented at an angle of 90° with respect to the first.

To calculate the final intensity of light after passing through three polarizing filters, we can use the law of Malus, which states that the intensity of light after passing through a polarizing filter is given by I = I0 cos² θ, where I0 is the initial intensity, and θ is the angle between the direction of polarization and the axis of the filter.

After passing through the first filter, the intensity of the unpolarized light is halved, so I1 = 0.5I0. Then, using the law of Malus, after passing through the second filter, I2 = I1 cos² 34° = 0.5I0 cos² 34°. Finally, the third polarizer is oriented at an angle of 90° with respect to the first, so no light is transmitted by this filter, and I3 = I2 cos² 90° = 0. Thus, the final intensity of light after passing through all three filters is 0% of the original intensity.

Learn more about Polarizing filters

Answer 2

When three polarizing filters are placed at specific angles, the final intensity of unpolarized light passing through them will be reduced to zero.

Step-by-step explanation:

To determine the percentage of the original intensity of unpolarized light that will remain after passing through the three polarizing filters, we need to consider the angles between the filters and their transmission axes.

The first filter reduces the intensity to 90% of its original value, while the second filter reduces it to 50% (cos(45°)² = 0.5). Finally, the third filter, which is at an angle of 90° with respect to the first, reduces the intensity to zero.

Therefore, the final intensity would be 0% of the original intensity, meaning no light would pass through all three filters.