Interesting light question in the GMAT

slind1 · #1 12-10-2005, 06:46 PM

I was studying for my upcoming GMAT exam and ran across a very interesting light related question that I thought I would share.

For a light that has an intensity of 60 candles at its source, the intensity in candles, S, of the light at a point d feet from the source is given by the formula S = 60k/d^2, where k is a constant. If the intensity of the light is 30 candles at a distance of 2 feet from the source, what is the intensity of the light at a distance of 20 feet from the source?

a. 3/10 candle
b. ½ candle
c. 11/3 candles
d. 2 candles
e. 3 candles

Radio · #2 12-10-2005, 06:49 PM

It is called the inverse square law and applies to all forms of electromagnetic radiation including Light, lots of info on google

slind1 · #3 12-10-2005, 07:11 PM

Quote:

Originally Posted by Radio

It is called the inverse square law and applies to all forms of electromagnetic radiation including Light, lots of info on google

Thanks, I saw the inverse square law on a site but it was expressed a little differently but interesting none the less. What I found interesting was that it showed up in an exam to get into B-school. Small world I guess.

Thanks for the info.