A) \[\frac{5}{214}\]
B) \[\frac{14}{205}\]
C) \[\frac{619}{1000}\]
D) \[\frac{5}{214}\]
Correct Answer: B
Solution :
The refractive index of the material of the lens and hence, the focal length of the lens is different for different colours known as chromatic aberration. The expression for chromatic aberration is \[{{f}_{R}}-{{f}_{B}}=\omega {{f}_{y}}\] where, \[{{f}_{R}},\,{{f}_{B}}\] and \[{{f}_{\gamma }}\]are focal lengths of red, blue and yellow light and \[\omega \]is dispersive power. Putting the numerical values, we have \[\omega =\frac{{{f}_{R}}-{{f}_{B}}}{{{f}_{\gamma }}}=\frac{21.4-20}{20.5}\] \[\omega =\frac{14}{205}\]You need to login to perform this action.
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