If the refractive indices of crown glass for red, yellow and violet colours are respectively μR, μY and μV, then the dispersive power of this glass would be

Question

If the refractive indices of crown glass for red, yellow and violet colours are respectively μR, μY and μV, then the dispersive power of this glass would be (A) (μV-μY/μR-1) (B) (μV-μR/μY-1) (C) (μV-μY/μY-μR) (D) (μV-μR/μY)-1

Tardigrade Admin · Accepted Answer

ω=(δV-δR/δ text mean ) =((μV-1) A-(μR-1) A/(μY-1) A) For δ text mean , we take yellow as mean of violet and red. ⇒ ω=(μV-μR/μY-1)

Q. If the refractive indices of crown glass for red, yellow and violet colours are respectively $μ_{R}, μ_{Y}$ and $μ_{V},$ then the dispersive power of this glass would be

$\frac{μ _{V} - μ _{Y}}{μ _{R} - 1}$

$\frac{μ _{V} - μ _{R}}{μ _{Y} - 1}$

$\frac{μ _{V} - μ _{Y}}{μ _{Y} - μ _{R}}$

$\frac{μ _{V} - μ _{R}}{μ _{Y}} - 1$

$ω = \frac{δ _{V} - δ _{R}}{δ _{mean}}$
$= \frac{( μ _{V} - 1 ) A - ( μ _{R} - 1 ) A}{( μ _{Y} - 1 ) A}$
For $δ_{mean},$ we take yellow as mean of violet and red.
$\Rightarrow ω = \frac{μ _{V} - μ _{R}}{μ _{Y} - 1}$

Q. If the refractive indices of crown glass for red, yellow and violet colours are respectively μR​,μY​ and μV​, then the dispersive power of this glass would be

μR​−1μV​−μY​​

μY​−1μV​−μR​​

μY​−μR​μV​−μY​​

μY​μV​−μR​​−1