The focal length of a thin convex lens for red and blue colours is 100.5 cm and 99.5 cm .The dispersive power of the lens isA. 0.01B. 0.02C. 1.005D. 0.995

The focal length of a thin convex lens for red and blue colours is 100

1.	The focal length of a thin convex lens for red and blue colours is 100.5 cm and 99.5 cm .The dispersive power of the lens isA. 0.01B. 0.02C. 1.005D. 0.995
Answer» Correct Answer - A (a) We have, `f_(y)=sqrt(f_(R)f_(b))` `f_(y)=sqrt(100.5xx99.5)=99.99` Also, omega=`(f_(R)-f_(b))/(f_(y))=(100.5-99.5)/99.99` Dispersive power,omega=`1/99.99=0.01`

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The focal length of a thin convex lens for red and blue colours is 100.5 cm and 99.5 cm .The dispersive power of the lens isA. 0.01B. 0.02C. 1.005D. 0.995

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