Q.No.139: - Define
phosphorescent also describe the factors upon which it depends.
Ans: - Objects that
continue to glow longer than 10-8s after the source of the
excitation is removed are called phosphorescent and the material that causes this
effect is called phosphor. For example, dial of clock. It depend on the
duration of light emission after the source of excitation is removed.
Showing posts with label excitation. Show all posts
Showing posts with label excitation. Show all posts
Friday, 8 November 2013
Q.No.138: - What is meant by fluorescent? On which factor it depends?
Q.No.138: - What is
meant by fluorescent? On which factor it depends?
Ans: - Objects in
which the emission of light ceases immediately (within
10-8s)
after the excitation is removed are called fluorescent. It depends upon the
duration of light emission after the source of excitation is removed. The
example is fluorescent lamp.