Luminous intensity

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/luminous-intensity

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is luminous intensity?Luminous intensity is a measure of how bright a light is in a particular direction. It is defined as the luminous flux per unit solid angle and is measured in candelas (cd).
2. Why is luminous intensity measured in a specific direction?Because light can shine differently in different directions, luminous intensity tells us how much light is coming from a point source in one chosen direction. It uses a unit called a solid angle to describe that direction.

Radiant Intensity: The power emitted by a light source per unit solid angle, measured in watts per steradian.
Luminous Flux: The total amount of visible light emitted by a source per unit time, measured in lumens.
Illuminance: The amount of luminous flux incident on a surface per unit area, measured in lux.