# CHAPTER20 : DISPERSION AND SPECTRA¶

## Example E1 : Pg 435¶

In :
# developed in windows XP operating system 32bit
# platform Scilab 5.4.1
#clc;clear;
# example 20.1
# calculation of the printersive power of the flint glass

# given data
mur=1.613# refractive index of flint glass for the red light
mu=1.620# refractive index of flint glass for the yellow light
muv=1.632# refractive index of flint glass for the violet light

# calculation
w=(muv-mur)/(mu-1.)# definition of the printersive power

print'the dispersive power of the flint glass is',w

the dispersive power of the flint glass is 0.0306451612903


## Example E2 : Pg 435¶

In :
# developed in windows XP operating system 32bit
# platform Scilab 5.4.1
#clc;clear;
# example 20.2
# calculation of the printersive power of the material of the lens

# given data
fr=90.# focal length(in cm) for the red light
fv=86.4# focal length(in cm) for the violet light

# calculation
# (1/f) = (mu-1) * ((1/R1) - (1/R2))
# muv - 1 =K/fv.....and.....mur - 1 = K/fr
# let m = muv - mur and K = 1
m=((1./fv)-(1./fr))
# muy - 1 = ((muv + mur)/2) - 1 = (K/2)*((1/fv) - (1/fr))
# let n = muy -1 and K = 1
n=(1./2.)*((1./fv)+(1./fr))
# w = (muv-mur)/(mu-1).........definition of the printersive power
w=m/n

print'the dispersive power of the material of the lens is',w

the dispersive power of the material of the lens is 0.0408163265306


# WORKED EXAMPLES¶

## Example E1w : Pg 440¶

In :
# developed in windows XP operating system 32bit
# platform Scilab 5.4.1
#clc;clear;
# example 20.1w
# calculation of the angular printersion produced by a thin prism of the flint glass

# given data

mur=1.613# refractive index of flint glass for the red light
muv=1.632# refractive index of flint glass for the violet light
A=5# refracting angle(in degree)

# calculation
delta=(muv-mur)*A# angular printersion

print'the angular dispersion produced by the thin prism of the flint glass is',delta,'degree'

the angular dispersion produced by the thin prism of the flint glass is 0.095 degree


## Example E2w : Pg 440¶

In :
# developed in windows XP operating system 32bit
# platform Scilab 5.4.1
#clc;clear;
# example 20.2w
# calculation of the angle of flint glass prism and angular printersion produced by the combination

# given data
A=5.# angle of crown glass prism(in degree)
mur=1.514# refractive index of crown glass for the red light
mu=1.517# refractive index of crown glass for the yellow light
muv=1.523# refractive index of crown glass for the violet light
murdash=1.613# refractive index of flint glass for the red light
mudash=1.620# refractive index of flint glass for the yellow light
muvdash=1.632# refractive index of flint glass for the violet light

# calculation
# delta = (mu - 1) * A.......deviation produced by the prism
# D = ((mu - 1)*A) - ((mudash - 1)*Adash)....net deviation
# net deviation for the mean ray is equal to zero
Adash=((mu-1)/(mudash-1))*A# angle of flint glass prism
# deltav - deltar = (muv - mur)*A.........................for crown glass prism
# deltavdash - deltardash = (muvdash - murdash)*Adash...for flint glass prism

print'the angle of flint glass prism needed is',Adash,'degree'
print'the angular printersion produced by the combination is',abs(delta),'degree'

the angle of flint glass prism needed is 4.16935483871 degree
the angular printersion produced by the combination is 0.0342177419355 degree


## Example E3w : Pg 441¶

In :
# developed in windows XP operating system 32bit
# platform Scilab 5.4.1
#clc;clear;
# example 20.3w
# calculation of the refracting angles of the two prisms

# given data
w=0.03# printersive power of crown glass
wdash=0.05# printersive power of flint glass
delta=1# deviation(in degree) produced
mu=1.517# refractive index for crown glass
mudash=1.621# refractive index for flint glass

# calculation
# w = (muv - mur)/(mu - 1)........printersive power
# (muv - mur)*A = (mu-1)*w*A......angular printersion
m=((mu-1.)/(mudash-1.))*(w/wdash)

the refracting angle of the crown prism is 4.83558994197 degree