Mastering The Inverse Square Law Of Light Intensity

This video tutorial explains the inverse square law using a light bulb example. It demonstrates how the intensity of light changes with distance, showing that intensity is inversely proportional to the square of the distance. The video includes calculations for different distances and a word problem to illustrate the concept further.

What does the inverse square law describe in relation to a light source?

• The relationship between power and distance

• The relationship between power and color

• The relationship between intensity and distance

• The relationship between intensity and color

Which formula represents the intensity of light according to the inverse square law?

• Intensity = Power / (4πr²)

• Intensity = Power x (4πr²)

• Intensity = Power / Distance

• Intensity = Power x Distance

If the distance from a light source is doubled, what happens to the intensity?

• It reduces to one-half

• It remains the same

• It doubles

• It reduces to one-fourth

What is the intensity of light at 3 meters if it is 360 watts per square meter at 1 meter?

• 120 watts per square meter

• 90 watts per square meter

• 40 watts per square meter

• 160 watts per square meter

How does the intensity change if the distance is tripled?

• It reduces by a factor of 3

• It remains the same

• It reduces by a factor of 6

• It reduces by a factor of 9

If the distance is quadrupled, by what factor does the intensity reduce?

• 32

• 4

• 8

• 16

What happens to the intensity if the distance is halved?

• It increases by a factor of 2

• It increases by a factor of 4

• It decreases by a factor of 2

• It decreases by a factor of 4

What is the intensity of light at 3 meters if it is 800 watts per square meter at 4 meters?

• 1422.2 watts per square meter

• 600 watts per square meter

• 200 watts per square meter

• 1000 watts per square meter

What is the formula to find the new intensity when the distance changes?

• I2/I1 = r1²/r2²

• I2/I1 = r2/r1

• I2/I1 = r1/r2

• I2/I1 = r2²/r1²

In the word problem, what is the initial intensity at 4 meters?

• 400 watts per square meter

• 600 watts per square meter

• 800 watts per square meter

• 1000 watts per square meter