Question

It has been proposed that automobile windshields and headlights should have polarizing filters to reduce the glare of oncoming lights during night driving. Would this work? How should the polarizing axes be arranged? What advantages would this scheme have? What disadvantages?

Short answer

Yes, this configuration would work. Polarizing axes should be arranged perpendicularly. The advantage of this scheme is glare gets reduced. The disadvantage of this scheme is reduced visibility for drivers.

Step-by-step solution

Definition of Polarization

The process of transforming unpolarized light into polarized light is known as polarization.

Polarized light waves are the light waves in which the vibrations occur in a single plane.

Determine whether configuration work or not and its polarizing axes arrangement.

The proposed configuration that automobile windshields and headlights should have polarizing filters to reduce the glare of oncoming lights during night driving would work.

Advantages and disadvantages of the proposed scheme

The main advantage of the proposed scheme is that it will help drivers to drive vehicles at night easily.

The disadvantage of the proposed scheme would be reduced visibility for the driver behind the windshield and reduction of light intensity of the headlights. The driver behind the windshield observes through the windshield objects in front of the car that emit or reflect light. Since this light is usually not polarized, the intensity of this light would be reduced after its polarization by passing through the windshield. Also, energy supplied by the car battery to the headlights would be dissipated on the polarizing filter, since the bulb in the headlights produces unpolarized light. After the polarization of this light on the polarizing filter that would be placed over the headlights, the intensity of the light would be reduced.

Hence, the proposed scheme would work, it will reduce glare that helps drivers to drive a car at night is the advantage, whereas energy supplied by the car battery gets dissipated on the polarizing filter is the disadvantage.