Optics Question 502
Question: A point source of 100 candela is held 5m above a sheet of blotting paper which reflects 75% of light incident upon it. The illuminance of blotting paper is
Options:
A) 4 phot
B) 4 lux
C) 3 phot
D) 3 lux
Show Answer
Answer:
Correct Answer: B
Solution:
$ I=\frac{L}{r^{2}}=\frac{100}{5^{2}} $ =4 Lux.
