Associate Certified Electronics Technician (CET) Practice Exam

In an LCD (Liquid Crystal Display), the liquid crystal molecules are known for their ability to manipulate polarized light. When polarized light enters the liquid crystal layer, the orientation of the liquid crystal molecules can change depending on the applied electrical field.

In a standard twisted nematic LCD, the liquid crystal structure is designed to twist the plane of polarized light by 90 degrees as it passes through. This means that light entering with one polarization becomes oriented in a different direction upon exiting the liquid crystal layer, allowing the light to pass through another polarizer aligned with this new angle. This twisting mechanism is essential for controlling the light and creating the visible images on the screen.

The other choices are not applicable as they represent different degrees of light rotation that do not correspond to the typical operation of a standard LCD panel. Therefore, the correct answer accurately reflects the fundamental property of how the liquid crystal fluid operates within an LCD.