Intensity of Light and Inverse Square Law

This video tutorial explains the inverse square law using a light bulb as an 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 bulb?

• The color of the light emitted

• The intensity of light based on distance

• The temperature of the light bulb

• The shape of the light bulb

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

• Intensity = Power - Distance

• Intensity = Power + Distance

• Intensity = Power / (4πr²)

• Intensity = Power x Distance

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

• It becomes one-half

• It becomes one-fourth

• It remains the same

• It doubles

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 remains the same

• It reduces by a factor of 6

• It reduces by a factor of 9

• It reduces by a factor of 3

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

• 600 watts per square meter

• 400 watts per square meter

• 800 watts per square meter

• 900 watts per square meter

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

• 1000 watts per square meter

• 400 watts per square meter

• 600 watts per square meter

• 800 watts per square meter

What is the formula used to find the new intensity in the word problem?

• i2 = i1 x (r2/r1)²

• i2 = i1 x (r1/r2)²

• i2 = i1 / (r2/r1)²

• i2 = i1 / (r1/r2)²

What is the calculated intensity at 3 meters in the word problem?

• 1200 watts per square meter

• 1422.2 watts per square meter

• 1600 watts per square meter

• 1800 watts per square meter

What happens to the intensity as you move closer to the light source?

• It remains constant

• It decreases

• It fluctuates

• It increases