The focal length of a glass lens for red and violet lights are 100 and 96.8cm respectively. Find the dispersive power of the glass.
Answers
Answered by
0
Answer:
According to the problem the focal length of lens red and violet are 100 cm and 96.8 cm respectively.
we know that, if focal length is f
then,
1/f = (μ−1)(1/R1 - 1/R2)
=> (μ−1) = K/f
where K = 1/(1/R1 −1/R2)
let fv= focal length for violet, fr = focal length for red.
μv is the coefficient of violer and μr is for red.
μv −1 = K/fv & μr −1 = K/fr
μv − μr = K (1/fv − 1/fr)
Dispersive power = ω = μv − μr = K (1/fv − 1/fr)
Now if we put all the focal length values for violet and red we will get th dispersive power.
Similar questions