A convergent doublet of separated lenses, corrected for spherical aberration, has resultant focal length of $10 c m$ . The separation between the two lenses is $2 c m$ . The focal lengths of the component lenses

18 c m, 20 c m

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10 c m, 12 c m

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12 c m, 14 c m

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16 c m, 18 c m

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Solution

The correct option is A $18 c m, 20 c m$
By using formula
$f = \frac{f_{1} f_{2}}{f_{1} + f_{2} - d}$
By trial and error method
Putting all option value one by one
For A we get f = 10 cm which is given
So option A is correct

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A convergent doublet of separated lenses, corrected for spherical aberration, has resultant focal length of 10cm. The separation between the two lenses is 2cm. The focal lengths of the component lenses

The correct option is A 18cm,20cmBy using formulaf=f1f2f1+f2−dBy trial and error method Putting all option value one by oneFor A we get f = 10 cm which is given So option A is correct

A convergent doublet of separated lenses, corrected for spherical aberration, has resultant focal length of $10 c m$ . The separation between the two lenses is $2 c m$ . The focal lengths of the component lenses

The correct option is A $18 c m, 20 c m$
By using formula
$f = \frac{f_{1} f_{2}}{f_{1} + f_{2} - d}$
By trial and error method
Putting all option value one by one
For A we get f = 10 cm which is given
So option A is correct