GED Science TestPhysical ScienceMedium
A technician is calibrating a sensor that measures light intensity. They notice that when the light source is moved farther away, the intensity measured by the sensor decreases. This observation is consistent with which principle of light propagation?
- AInverse Square Law
- BPolarization
- CDiffraction
- DRefraction
Show answer & explanationAnswer & explanation
Correct answer: A. Inverse Square Law
The Inverse Square Law states that the intensity of a physical quantity (like light or sound) is inversely proportional to the square of the distance from the source. As distance increases, intensity decreases rapidly.
Why the other options are wrong
- B. Polarization refers to the orientation of oscillations in a transverse wave, not the change in intensity with distance.
- C. Diffraction is the spreading of waves as they pass through an aperture or around an obstacle, not directly related to intensity drop with distance from source.
- D. Refraction is the bending of light as it passes from one medium to another, not related to intensity over distance.
Inverse Square Law
The Inverse Square Law states that the intensity of a physical quantity (such as light, sound, or gravity) is inversely proportional to the square of the distance from the source.
- As distance doubles, intensity becomes one-fourth.
- Applies to phenomena radiating uniformly in all directions.
- Fundamental concept in physics, astronomy, and engineering.
Memory trick: Light is 'Inversely Squared' for distance, like a faint star.