Inverse Square Law of Illumination Quiz

A lighting engineer is tasked with designing the illumination for a museum exhibit. Using the inverse square law, how should the engineer adjust the distance between the light source and the exhibit to double the illumination on the display?

• Move the light source twice as far from the exhibit.

• Move the light source half as far from the exhibit.

• Move the light source to the same distance as before.

• Move the light source three times as far from the exhibit.

A photographer wants to ensure that the lighting on a subject is reduced to one-fourth its original intensity. According to the inverse square law, what should the photographer do with the distance between the light source and the subject?

• Double the distance.

• Halve the distance.

• Keep the distance the same.

• Triple the distance.

In a laboratory experiment, a student observes that the illumination on a surface decreases as the distance from the light source increases. Which principle best explains this observation?

• Law of Reflection

• Inverse Square Law

• Law of Refraction

• Law of Conservation of Energy

A city planner is designing street lighting and wants to ensure even illumination along a road. How can the inverse square law inform the placement of streetlights?

• Place lights at random intervals.

• Place lights closer together as the distance from the power source increases.

• Place lights farther apart as the distance from the power source increases.

• Place lights at equal intervals, but adjust their height based on the inverse square law.

A scientist is measuring the intensity of light at various distances from a point source. If the intensity at 2 meters is 100 lux, what would the intensity be at 4 meters, according to the inverse square law?

• 25 lux

• 50 lux

• 200 lux

• 400 lux

Which of the following real-world applications relies most directly on the inverse square law of illumination?

• Calculating the speed of sound

• Designing solar panel arrays

• Determining the brightness of stars as seen from Earth

• Measuring the mass of an object

A student is asked to explain why the brightness of a lamp appears to decrease rapidly as they walk away from it. Which reasoning best applies?

• The lamp’s power output decreases with distance.

• The light spreads out over a larger area, following the inverse square law.

• The lamp absorbs more light as distance increases.

• The color of the light changes with distance.

If a light source is moved from 3 meters to 6 meters away from a surface, how does the illumination on the surface change according to the inverse square law?

• It becomes four times greater.

• It becomes one-fourth as great.

• It remains the same.

• It becomes twice as great.

A lighting designer wants to achieve a specific illumination level on a stage. If the distance from the light to the stage is tripled, what must be done to the power of the light source to maintain the same illumination, according to the inverse square law?

• Increase the power by a factor of 3

• Increase the power by a factor of 6

• Increase the power by a factor of 9

• Decrease the power by a factor of 3

Which scenario best demonstrates the application of the inverse square law in everyday life?

• Adjusting the volume of a speaker in a room

• Moving a reading lamp closer to a book to make the text brighter

• Changing the color of a light bulb

• Using a magnifying glass to focus sunlight